set latest svn information in revstamp.h.  removed empty changelogs.
marked the current state as stable in _mingw.mac.h.

git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/stable/v2.x@4535 4407c894-4637-0410-b4f5-ada5f102cad1
21 files changed