Updating revisions.pl.in: - Change the way the LLVM SVN revision is detected, using `svn info` instead of `svnversion`. This speeds it up significantly on my machine (especially when the LLVM SVN checkout isn't in disk cache). - Add "last changed date" to SVN checkouts too, not just unpacked tarballs - No longer rely on SVN revision to detect release vs trunk checkouts, treat release checkout the same as unpacked release tarball. (Except for date determination, which uses SVN date instead of filesystem date)