Update to ipython 2.1.
	modified:   requirements.txt
Actually Make snapshot optional.
	modified:   api/volume.py
	modified:   service/volume.py
Merge branch 'abyssinian-nightjar' of github.com:iPlantCollaborativeOpenSource/atmosphere into abyssinian-nightjar
Move query out of the models directory, since it's not a model.

Refactor other references to it.

	modified:   api/serializers.py
	modified:   core/models/application.py
	renamed:    core/models/query.py -> core/query.py