generic temporary work folder causing overwriting issues

[rhs2132]

I was running multiple povme processes in the same folder and getting confusing results. I figured out that povme creates a work folder (.povme_tmp) in the current directory with subfolders (i.e. frame_1.pym) only identified by frame number. Since I was running multiple processes, each was overwriting the others and the result was essentially random.

I have now separated my runs into separate working directories, but uniquely identifying the work directory or frame directories with some string unique to the run would eliminate this issue.

[j-wags]

Thanks for the suggestion, @rhs2132. If you're still out there -- I agree that attaching a differentiating string to the temporary folder would solve this problem.

Per my comments in #30, it would be good to determine whether this project is worth maintaining. I see that you went and developed PyVol, and it's possible that may be a better place to consolidate effort. Let me know if you have any thoughts.