Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Prepare for the removal of set_rcvar() by changing the rcvar=
assignments to the literal values it would have returned.

The concept of set_rcvar() was nice in theory, but the forks
it creates are a drag on the startup process, which is especially
noticeable on slower systems, such as embedded ones.

During the discussion on freebsd-rc@ a preference was expressed for
using ${name}_enable instead of the literal values. However the
code portability concept doesn't really apply since there are so
many other places where the literal name has to be searched for
and replaced. Also, using the literal value is also a tiny bit
faster than dereferencing the variables, and every little bit helps.

Remove trailing white space. No functional changes.

As previously discussed, add the svn:executable property to all scripts

Add rfcomm_pppd_server rc script to allow start rfcomm_pppd(8) in server
mode at boot time. Multiple profiles can be started at the same time.
The whole idea is very similar to the ppp rc script.

Document Bluetooth knobs in rc.conf(5)

MFC after: 1 week