[Queue-developers] Fix for automounted systems path

[W. G. K. <wer...@ya...>]

This is a fix for getting the current directory on some automounted
systems, where the path is slightly different on each system. getcwd()
doesn't work, but getenv("PWD") does work on these systems.

I'm not sure whether this fix is generally applicable, because it would
let users do a "setenv PWD whatever" and then have Queue "chdir" to this
directory, which might be undesirable. PWD is set by the shell, so it
would also only be reliable when queue is called by a shell program.
However, it might be useful to some users, so is posted here.