Add os_trace_extensions.c.

os_trace_extensions.c extends os_trace to have extra functionality. All
the criteria in it are globbing criteria.

Add ACCOUNT trace criteria. This criteria matches against all nicknames
registered to the user.

Add GECOS trace criteria. To do a search for a multi-word gecos, quote
your search parameter, e.g., OS TRACE GECOS "some user*".

Added HOST trace criteria.

Added IP trace criteria.

Added NICK trace criteria.

Added USER trace criteria.