libbsd: Add kerel trace support

[chrisj at rtems.org]

This patch set addis trace support, a lockmgr and proc0 to libbsd.

The patch set is part of adding NFSv4 to libbsd. This involves adding VFS
and refactoring the syscall interfaces and tracing is an important part
of the long term maintenance of these features.

Part of this is adding a proc0. RTEMS is a single process system and
this is the single process libbsd needs.

VFS uses the lockmgr. Add support.

Chris