specfile cleanups

specfile cleanups

Some specfile cleanups after the split.
- zlib dependency fix, current method is inconsistent, you can
  potentially build a package that you can't install on machine you
  built it on
- Add proper defattr
- Remove trailing '.' in summary
- Add docs to split up packages
- Add git-core dependency for each subpackage
- Move arch import to separate package as well

Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>