This will greatly help us to structure the functionality and commands in
a more sane way. We will distribute the sources as actual libraries and
reuse code with imports instead of processing everything with m4 and
duplicating a lot of code.
This allows us to reuse the code and have the conversion in a single
place instead of cluttering rules across different execution units.
It also fixes the implementations according to the specs of
git-check-ref-format.
Signed-off-by: Levente Polyak <anthraxx@archlinux.org>