tmp dir is now always accessible to user; fixes #62
updated to version from qiime/pycogent_bacports
updated so user has control over where temp files are written, fixes #62
updated so stdout and stderr files are not written to /tmp
Merge pull request #65 from gregcaporaso/issue-62

improved output file names (ported fix from qiime's pycogent backports) and gives user control over temp file location