Add d.o-specific validation during pushes to Git for contrib projects

As per a thread on the devel list, it'd be nice to catch bogus .info files (e.g. when contribs claim to be part of core, etc) and perhaps some other basic checks from the coder module, right when someone's trying to commit something to the contrib CVS repo, instead of only noticing problems once we're trying to package a release.

We already have php code that runs to validate commits (the xcvs-* scripts from the CVS integration module), it just doesn't look at the contents of the file, only the user trying to make the commit, the directory where the file lives, and the CVS access control tables in the DB.

Of course, stuff like coder.module checks and validating .info files is utterly specific to drupal.org, not something we'd want to fold into the "upstream" version of xcvs-commitinfo.php, but we could certainly tie into that script with some d.o-specific local modifications that do whatever additional validation we want. Better yet, we should probably just have a 2nd script invoked by CVSROOT/commitinfo that does this additional validation, *after* xcvs-commitinfo.php returns. That's probably cleaner all the way around...

We just have to:

A) Figure out exactly what checks we want to do.
B) Write a script to enforce them.
C) Put that script ino CVSROOT/commitinfo, after the xcvs-commitinfo.php invocation

I can certainly do C if others step up and provide A and B.

Cheers,
-Derek