jack.pc.in:
Add the custom `jack_implementation=jack1` pkgconfig variable to the
generated jack.pc file to be able to distinguish jack implementations.
As jack implementations exist with jack1, jack2 and pipewire-jack, it is
not (easily) possible to distinguish them by looking at the version
alone (particularly the case with jack2 vs. pipewire-jack, as they share
the same headers).
- replaced use of g_snprinf with snprintf (snprintf is a standard
POSIX/ANSI-C routine so there's no need to use glib here)
- removed all dependencies to glib from source code and makefiles
- added documentation of JACK versioning to configure.in
- incremented JACK version to 0.40.0
git-svn-id: svn+ssh://jackaudio.org/trunk/jack@256 0c269be4-1314-0410-8aa9-9f06e86f4224