HUE-2176 [oozie] Progress report on dashboard can slow the page a lot

Adding an API to get the Oozie logs of any job:
e.g.
http://127.0.0.1:8000/oozie/get_oozie_job_log/0000028-140711130513496-oozie-oozi-W
HUE-2176 [oozie] Changed refresh intervals

Removed log from returned workflow/coord/bundle JSON
Separate call to the new getLog
HUE-2123 [beeswax] Handle cancel state properly