Changed how project-workflow mapping is retrieved
The mapping is now retrieved using extend=workflow parameter instead of
requesting through /project/id/workflows. One of the advantage is that
all mappings can be retrieved at once. This also reduces unnecessary
fields such as workflow_steps
Removed unecessary fields in backlog item classes
Removed most of *Object fields such as projectObject since only the id
is ever used.
Added ability to retrieve and save escaltions and escalation levels
Added ability to view and edit escalation level for incidents