Announce 10.1-RC1.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45715 c2e8774f-c49f-e111-b436-862b2bbc8956
Switch 10.1 betarel.version to RC1

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45716 c2e8774f-c49f-e111-b436-862b2bbc8956