Created new branch central-eliminate-fabric
Eliminate the use of fabric when executing commands defined in an <action type="shell_command"> tag.
Code cleanup, documentation.
Use the provided use_fabric parameter in handle_command.
Merged in davebgx/galaxy-central/central-eliminate-fabric (pull request #330)

Eliminate use of fabric when executing tool dependency recipes' shell_command actions.
Fix failing api search test.
Fix mock-requests PUT action.

Should fix failing history import/export test on buildbot server that doesn't have requests dependency available.