Physical Location Fixes/Enhancements

Physical Location Fixes/Enhancements

Teach the physical location retrieval function about using an ENV var.

This allows a subdomain to force a specific physical location, say by adding
to their apache config:

SetEnv physical_loc 4

Rewriterules could also be used for more dynamic configuration.

Also, as a fix:

Have preferred library use the stored physical location instead of assuming
that CGI has the setting all the time.

Signed-off-by: Thomas Berezansky <tsbere@mvlc.org>