Do the disable more properly and add an api to remove disable

1. add _reenable() to mark status to FAILED, set disabled to False and clear
   failure queue
2. clean up some code and states
3. add test coverage for disable
4. add remove disable
add a new test for disable then done
renable _reenable to re_enable
add the re-enable button (wip, button works, but no feedback)
will decrease the count and remove row
Adds luigi_state tracking to interface
Removes actual_complete scheduling parameter
Removes unused _complete_cache
fixed when the task is disabled by worker and cannot re-enabled
Merge branch 'disable_disable'