Enable workqueue-sharedfs in Makeflow.

Monitor wrapping does not seem to work, but I was able to run shrimp on
pscratch using absolute paths.
Makeflow uses absolute paths when -Twq_sharedfs

This does not work when a directory needs to be created (e.g., with the
monitor).
do_thirdput creates directory if needed

Patch per Mike suggestion.
Merge pull request #166 from btovar/wq_sharedfs

Enable workqueue-sharedfs in Makeflow.