Add/update files in POTFILES.in and fix make check
Remnove autogenerated files
as-version.m4 not used, remove it
as-ac-expand.m4 not used. remove it
just use MATE_COMPILE_WARNINGS(maximum) and remove custom macros
Remove custom macros from EXTRA_DIST
Remove 2 forgotten autogenerated files
Correct EXTRA_DIST
Generate ChangeLog from git log
Make tar.xz instead of tar.bz2
Merge pull request #33 from infirit/1.6

Cherry pick from master and remove unused/autogenerated files