Overview of changes:

 *  build target will now leave file .mkit/semver file

    Build tools can read this to easily find out version.

 *  semver() caches its output now

 *  Refactored common operations in .mkit

 *  Removed old unnecessary check

 *  Solved or muted last few ShellCheck issues

To make it easier for build tools to read full version information.

A bit convoluted check that cannot fail, since everything now relies on
var.sh being imported, which is guarranteed to set $MKIT_LOCAL to a
non-empty value.

Overview of changes:

 *  mkit/stub: Removed `[roots]` reference from `[tokens]` example

    Using '[roots]' as reference can have unpredictable results since it
    silently depends on DESTDIR, which is only available at install
    time.

    Next breaking release (v0.1.0, but could be earlier as we are still
    in 0.0.z space) should rename 'roots' to 'ROOTS' to reflect its
    volatile nature (similar to ENV).

 *  mkit/stub: LICENSE.md won't be mentioned in headers if not asked

 *  mkit/stub: PREFIX is set to /usr in packaging templates

 *  mkit/stub: Added notes about file paths in packaging templates

 *  mkit/stub: Fixed bug when empty license name would be accepted

 *  mkit/stub: Fixed double deploy of template.spec

 *  mkit/make: Having relsrc same as reldst is now tolerated (albeit useless)

 *  mkit/make: 'release' and 'vbump' can now be reached directly (without GNU Make)

 *  mkit/make: Added -V option to mkit/make script

 *  Code maintenance

Defining same reldst as relsrc is useless, but does not harm, so we can
let it slip through.

Use of `[roots]` in `[tokens]` is tricky, because final value of a
`[roots:foo]` will "silently" depend on DESTDIR, while DESTDIR is
only known during install time.  On the other hand, `[tokens]` are used only
during build time.

In other words, YOU CANNOT RELY on the value of keys in `[roots]` to be
consistent.  For example, consider root:

    [roots]
        foo = /bar
        qux = [ENV:PREFIX]:/quux

`[roots:foo]` will be '/bar' at build time, but "$DESTDIR/bar" at
install time, and `[roots:qux]` will be "$PREFIX/quux" at build time,
but "$DESTDIR/$PREFIX/quux" at install time.

Just about only case when you might want to use it is mentioning it in
a document, when you want the value to be rather "standard" than
"correct", while you still want to respect PREFIX.

So let's not lead new users directly into that rabbit hole.

Usage of GNU Make really is just a sugar, so we should enable all
targets also for direct mkit/make invocation.

We have no tests so TFKit is useless here.

Overview of changes:

 *  Fixed version directive lookup

    mkit.ini would be refused if version directive was at the end of the
    file, while first and last 3 lines is what was supposed to work.

 *  Fixed license argument check

    stub script would ignore license argument due to argument validation
    error caused by refactoring.

 *  Fixed bad grep advice in MKIT_STUB_README.md

 *  Updated own dogfood

I don't know how I came up with that pipe but it's certainly wrong.

Earlier I replaced all checks on $License valiue when I should have
replaced all *but this one*.

Overview of changes:

 *  Rewrote *newstub* as *stub* meta-command, now with update mode

    The script looks promising, let's use the extensible CLI scheme.

 *  Removed sorting from `ini lskeys`

    *stub* can rewrite user's mkit.ini but it does not want to mess it
    up more than is necessary.

 *  User can now override project version with *stub*

 *  *stub* now Respects MKIT_INI environment variable

 *  Fixed problems with LICENSE.md and README.md rewriting in *stub*

 *  Moved MKit version directive to end of file

 *  Improved MKit's own project README.md

It does not work if the body is not trivial and narrow.

'newstub' was not so far to being able to update meta-data based on
existing mkit.ini.  However, in order to keep the CLI sane, it seems
better to switch to meta-command scheme.

For purpose of rewriting user's INI, we don't want to mess it up more
than is necessary.

Not everyone likes v0.0.0.  While it's trivial to change, the other
reason for this is scenario when user just updates (re-builds) the
meta-data.

Not everyone wants mkit.ini in the root.

Being consistent leads to much more readable code.

Try to show user also "why" they might want to do it.

Overview of changes:

 *  Added 'newstub', builder script to help with new projects

    The script is intended to help start up new MKit project by generating
    structure necessary for MKit to work, and instructing user which
    parts to review and how.

 *  Fixed bug when skeletons could be deployed as part of directory

    If directory targeted in [files] section contained .skel files, they
    would get deployed along with built files.

 *  Code refactoring

    Moved global variables to new vars.sh module, improved initialization
    and importing code and added file headers.

 *  Improved patch importer utility

We had to switch to recursive mode so that we can control more precisely
what gets installed.