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

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

Spelling fixes for usr.bin/

Handle the situation where fixups_close() has been called but more fixups
are still available on the queue.

Without this, the fixups producer/consumer pipeline will artifically terminate
before all of the fixups have been processed, leading to incomplete updates
and generally quite unhappy users.

Submitted by: mux

- Move csup away from contrib/ and into usr.bin/. Software is no longer
contributed, and main development is happening in the FreeBSD repo.

Suggested by: joel

This commit was generated by cvs2svn to compensate for changes in r156230,
which included commits to RCS files with non-trunk default branches.

Initial import of csup.