Atmosphere now uses rtwo.
rtwo is derived from Atmosphere's service app. More information can be
found at:

https://github.com/iPlantCollaborativeOpenSource/rtwo

As part of this change most of service has moved to rtwo. The remaining
functionality is specific to Atmosphere. Such as tasks, imaging and
account actions involving core.
Merge branch 'master' of github.com:iPlantCollaborativeOpenSource/atmosphere
Updates to connect rtwo with service.task and service.tasks.
	modified:   api/__init__.py
	new file:   service/task.py
Added docs/*.org to .gitignore