Merge pull request #24 from emonty/small_fixes

Small fixes

git-svn-id: https://svn.stsci.edu/svn/ssb/stsci_python/d2to1/trunk@23936 fe389314-cf27-0410-b35b-8c050e845b92
When catching exceptions from a setup-hook don't throw a traceback up for sys.exit()

git-svn-id: https://svn.stsci.edu/svn/ssb/stsci_python/d2to1/trunk@24204 fe389314-cf27-0410-b35b-8c050e845b92