- remove deprecated references to GNATS
- point users to community link off of main support page so they don't
have to dig for the information

Differential Revision:	 https://reviews.freebsd.org/D1120
Approved by:	wblock (mentor)


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45936 c2e8774f-c49f-e111-b436-862b2bbc8956