Proposed fix for Bugzilla bug #60

See http://www.clusterresources.com/bugzilla/show_bug.cgi?id=60 for details.

I've generalized David Beer's OriginalPath technique, cleaned up and streamlined some of the code, and applied it to both pbs_server and pbs_mom.

I was unable to test with the 4.1.4 tarball, so I'm hoping a fix can make it into 4.1.5 so that VLSCI and VPAC will have a reasonable upgrade strategy to obtain the fix.

Similar changes for "master" may be found on my kainx/torque.git/bug60-fix branch.