Otherwise we're not really testing "this" shellfu but the installed one.

This should have been all along; if SHELLFU_PATH is not preferred,
one cannot override it eg. in test runs.

Overview of changes:

 *  Re-packaged with better granularity

    Having multi-module packages such as 'shellfu-core' limits dependency
    control on user part.  Additionally, after splitting packages
    to one-per-module, we could move some of modules to 'sh' space,
    ie. increase their usability.

 *  Removed old 'sync' module

    Having one "wait" function does not really justify its presence in
    the main shellfu repo; if anyone needs it anyway, I can provide it
    as a separate package.

 *  Renamed binaries shellfu-doc and shellfu-get to sfpath and sfdoc

    Both were kind of hard to type.  "shellfu-get" was a bit too generic
    given that it really only prints path.  Also 'sfdoc' resembles other
    doc viewers such as 'perldoc' and 'pydoc'.

 *  Moved sfdoc to main package

    sfdoc can be useful everywhere Shellfu style is used; not just in
    Shellfu modules.

 *  Moved packages to /usr space

    Eventually, if packages should reach distributions, they should be
    there anyway.  Also it makes it easier to use Shellfu in
    environments where /usr/local/bin might be missing on PATH (eg. cron
    on debian).

 *  Improved and cleaned up lot of meta-data

    From SPEC file to debian directory to mkit.ini, there have been many
    changes in meta-data.

 *  Excluded shellfu_import test from Debian build time

    This test cannot succeed because it relies on shell features ouside
    POSIX that Debian's minimalistic dash does not implement.  The test
    will have to be rewritten; the issue is tracked here:

        https://github.com/AloisMahdal/shellfu/issues/1

 *  Added 'version' sub-command to shellfu()

    Now shellfu() function can report version of a Shellfu module.
    Versioning is not mandatory but can be useful for module unit tests
    to provide more rich reports.  (E.g. TF_HEADER in external module
    shellfu-bash-saturnin makes use of this)

 *  Refactored shellfu() a bit

 *  Made sfpath respect SHELLFU_DIR from environment

 *  Added warning in sfdoc if pod2man is missing

 *  Changed license to LGPLv2

 *  Fixed pretty.debug() bug that would hide caller name

 *  Fixed test bug with debug -v and Bash 4.4+

 *  Refactored tests a bit

 *  Added build-time tests

 *  Codebase maintenance

Add missing perl and ps dependencies and remove bash (because Essential
packages are not supposed to be there).

https://github.com/AloisMahdal/shellfu/issues/1

Bash 4.4 and later does not quote array declaration when `declare -p` is
used.

In the rare case when pod2man is not available, the usage options are
limited (one can still view pages in other modes or list functions
etc.).

Older Bash would let this get away since the output is used with form:

    read a b <<<$(_pretty__get_caller)

which joined the parts into single line, which happened to be what we
want.

Switch to packaging model where each module goes into separate package.

Such model makes much more sense (after all it's also how big platforms
such as python do it).  It allows better control over dependencies and
allows re-locating modules properly according to compatibility level
(i.e. now exit.sh can go to 'sh' despite the fact that in 'core' it had
to be with other Bash-compatible modules).

Not used anywhere these days

Mostly for consistency with the other two binaries.

'sfdoc' is easier to type and resembles 'pydoc' and 'perldoc' so it's
even easier to remember.

The only purpose of the binary is to show local Shellfu path and it's
in every single Shellfu script.  Let's save people some typing.

Since our package does not install or create anything in /usr/local,
dh_usrlocal won't try to do anything.

Decorate them and treat each argument as separate message (line)

Since __SHELLFU_DIR__ is not known at install time, its value is purely
"theoretical" and we need to be able to override it.

Overview of changes:

 *  Improved and updated README.md

    Actually, the main reason for this update is to make new README
    visible sooner, since it's been significantly improved.  Most
    important change is that the introduction has been moved to own
    document.  Also Installation section has been clarified.  That and
    some tiny fixes.

 *  Made minor visual improvement to mkusage()

 *  Added tests for mkusage() '-w' option

 *  Made SHELLFU_IMPORTED into an internal variable

 *  Added some ShellCheck exceptions

Yep, test suite is growing!

Give more space to packages.

There's no real reason to have it public.

SC2039 - We simply have to use `local` whenever it's possible, and
although it's not defined in POSIX, most common shells do support it
(well, at least Dash, Bash and Zsh).

SC1090 - Sourcing non-constant file is pretty much the main idea of
Shellfu, so avoiding that part does not make sense.

Overview of changes:

 *  Added workaround to shellfu_api test only against own modules

 *  Added option to append clarifying message to usage messages

    Usage messages can now be made more useful by warning user what
    exactly was wrong.  Warnings will appear after the usage message
    and before command exits and decorated with 'bad usage: ' prefix;
    this is so that user will be more likely notice and understand them.

    Note that this could be done earlier by using -E option and adding
    the warning yourself inside usage() function, but the -w option lets
    you keep usage() very simple and yet leads to more consistency.

 *  Codebase maintenance

 *  Refactored charmenu.sh

    The docstring was not very useful so this it was overhauled
    completely.  Also more proper coding style is now in place.

 *  `shellfu` command will now de-duplicate $SHELLFU_PATH

    shellfu init function, and by extension some shellfu-doc modes,
    would list a module twice if its path ended up twice on
    SHELLFU_PATH.  That should no longer happen.

 *  Added mdfmt, a Markdown formatting helper

    This module consists of single function with aim to help generate
    Markdown text from your scripts.

 *  Updated and improved usage-related pretty.sh docstrings

 *  Fixed PRETTY_DEBUG_EXCLUDE double double-underscore bug

    PRETTY_DEBUG_EXCLUDE would not work properly on functions like
    `foo__bar__baz`, where the second double-underscore would make it
    think module name was `foo__bar`, when in fact it's `foo`.

 *  Added journald logging module for pretty.sh

    Using systemd-cat, this module employs journald as way of
    communicating with user.

 *  Added shellfu-sh pseudo-package

    On RPM-based distributions, somebody has to own 'include-sh'
    directory.  Also having shellfu-FOO package helps module packages
    declare their "Shellfu flavor" (ie. `Requires: shellfu-sh` sends
    clear message that a module is "POSIX-oriented".

 *  Updated packaging and meta-data

    Files responsinle for packaging and versioning meta-data have been
    altered to catch up with newer versions of MKit.  This should have
    almost no effect on package (only 'effect' I can think of is a purely
    decorative change in `--version` output).

 *  Fixed typo in SPEC file

    SPEC file claimed that Shellfu is distributed under LGPL2, while
    it's actually GPL3.  (We should consider changing it to LGPL2,
    though.)

 *  Replaced LICENSE file with Markdown version

    Because Markdown is cooler.  For a more serious reason, MKit now has
    *newstub* script, which can help regenerate MKit structure including
    LICENSE file, and this script can only do Markdown (because Markdown
    is cooler).  TL;DR: It will be less hassle to keep MKit stuff fresh.

 *  Updated emnedded TFKit (v0.0.14) and MKit (v0.0.21)

Until TFKit is able to run tests in sandbox (instead of running tests
against installed SUT), this test will throw false positives in case
any other Shellfu modules are present.

This commit adds workaround that should be removed when new TFKit
version is installed.

After usage message, before exiting---that's the sweet spot.