Basically as a skeleton to see if this form could be used widely.

Now --version-patch does not print metadata, and -proper and -meta have
been added to filter particular part ("proper" semver field w/o
meta-data, or meta-data only).

If not in git (e.g. unpacked tarball), trust the tree and just use
VERSION from config.mk.

Otherwise, take newest tag, and if HEAD is tagged, use that tag
(without the initial "v").  If HEAD is newer, form build meta-data
field from shortened commit hash; furthermore if tree is "dirty" (i.e.
has some files modified, add ".dirty" to the version number.

For example, you just tagged the HEAD with v1.0.1, the version
number is therefore

    1.0.1

Now you edit a file.  At this moment if you build the project, the
version will be

    1.0.1+dirty

If you add + commit that change, the "dirty" has name now:

    1.0.1+ga34f8c

but now if you edit a file and re-build, you get "dirty" again:

    1.0.1+ga34f8c.dirty

In other words, anytime you see "dirty" in the version info, you know
that the tree was manually modified (which could mean anything from
fixing a typo to completely changing the code).

If there's only g??????, then the code has been modified as well, but at
least you may have reference to the actual tree.

At any rate, any version with any meta-data is purely internal and
should never be used for comparison (your tests should not rely on
version string comparison).

Similar to grep or test, 1 is reserved for "no", 2 is used for
"incorrect use/syntax"

Allow usage_is caller specify exit status or suppress exit completely

Since functions cannot start with '-' (and funky names are discouraged
anyway), it only adds more complexity to the arg router.

grep at the end of main pipe ensures not only correct exit status
but also throws away empty lines--but should not do it in strict
mode.

I.e. ffdoc works now.

Major rewrite of listing code.  New version is more readable, more
usable (no need for lsfun() in ffoom now)  and suports wildcards.

Fastfoo libraries are not intended for interactive sessions (use *fff*),
we are only enabling this to aid development and testing process.

Contains charmenu, a utility function to help define and utilize
interactive "character menu" as we know it from yum, apt, git and
many, many other CLI tools.

Since these files do not contain build-time anymore, they don't need to be processed by mk.sh as such, hence can have their final form

... so that we don't have to care if other modules have already created
it (as long as our path inside it is unique)

All this module does is create a temp directory FFOO_TMP, that can be
shared among modules.  This simplifies clenanup but should be only
used very rarely and only by modules (i.e. not by user code).