Move socket setup to set_socket(), called before the uid/gid change.

id2entry: when an error occurs attempting to insert fetched
entry into cache, check to see if entry was added by another
thread.  If so, return the entry added by the other thread.
The concurrency tests now run without the dreaded "no such object"
error messages!

Fix wait4child change: Prefer wait3 over wait. Use SIGNAL instead of signal.

Removed external include/library paths from projects.  External paths should
be set via Tools | Options | Directories.  This allows each developer the
freedom to install external libraries where they desire.
Used libdb.lib instead of libdbs.lib to avoid thread conflicts.
Added hs_regex.lib to library input.  We require some form of regex, this
library works (and is relatively easy for the user to install).
Removed a little lint which MCVC5 detected.
Need to sort out single-threaded vs multithreaded library generation.

and back-bdb2/compare.c.