Fixes bug 828906 - Remove obsolete code using branches table.
Show full traceback details with error in crontabber.
Merge pull request #1066 from rfw/show_error_in_list_jobs

Show full traceback details with error in crontabber.
Merge pull request #1046 from AdrianGaudebert/828906-remove-branches-support

Fixes bug 828906 - Remove obsolete code using branches table.
bug 834523 - ability to reset crontabber apps, r=rhelmer