get rid of agenthub support; update agent manager for celery environment.
move context back.
docstrings
unused.
Merge branch 'distributed-tasks' into jortel-distributed-tasks

Conflicts:
	server/test/unit/test_agent.py
docstrings and remaning for clarity.
docstrings.
add missing unit tests.
add missing unit tests.
docstrings.
Merge branch 'distributed-tasks' into jortel-distributed-tasks
remove heartbeat support not used by pulp 2.
missing distributor should raise an error.
return task_id to support rest API.
improved bind/unbind post processing.
pep8 fix.
Convert Bind Itineraries to use Celery Tasks
Fix base class for MockTaskResult
Fix errors in the exception class & add better descriptions to the hashtable comparison util
Fix flake8 & bugs