Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

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

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

style cleanup: Remove duplicate $FreeBSD$ tags.

These files had tags after teh copyright notice,
inside the comment block (incorrect, removed),
and outside the comment block (correct).

Approved by: rwatson (mentor)

Add an implementation of fabs() (which is quite trivial).
When it is called directly, gcc is smart enough to generate inline
code for it, which is why it wasn't noticed before that it was missing.

fabs() would probably better fit into libm, but it has traditionally been
in libc on FreeBSD, so there is probably software around that makes
assumptions about this by now.