Switch to the new beta numbering scheme.
* configure.ac: Remove svn code and add the usual git version numbering code. Build versioninfo.rc. * src/versioninfo.rc.in: New. * src/gpa-resource.rc: Include versioninfo.rc. * src/Makefile.am (EXTRA_DIST): Add versioninfo.rc.in. * src/helpmenu.c (gpa_help_about): Show the GIT commit id.