cleaning up xfce-dev-tools

[Natanael Copa]

Hi,

I feel an urgent need to clean up xfce-dev-tools a bit and get
completely rid of the .{ac,in}.in. Only use .ac (or .in).

I could probably help with cleaning things up but I need to know:
How do you guys want it to work?

I know you want git version string baked into the version string
without editing configure.ac every commit and I know you want the
LINGUAS stuff be dynamic and I have some ideas.

Any suggestions for an API? (we need be backwards compat so we dont
break existing configure.in.in)

While here, maybe replace XDT_CHECK_PACKAGE with PKG_CHECK_MODULE too
(or reimplement XDT_CHECK_PACKAGE to use PKG_CHECK_MODULE)?

Thanks!

-nc