VolumeName implementation.
Filesystems now expect volumes to have a VolumeName as their name.
Volume and VolumeService now use VolumeName for names.
Start switching IPC over to VolumeNames.
All flocker.volume tests pass.
Allow periods in identifiers.
Convert deployment logic to know just enough about namespaces.
Lint fixes.
Update documentation to note existence of namespaces.
My local spellchecker doesn't like "namespace".
Merge remote-tracking branch 'refs/remotes/origin/master' into volume-namespaces-771

Conflicts:
	flocker/volume/service.py
	flocker/volume/test/test_service.py
Fix data container integration.
Merge remote-tracking branch 'refs/remotes/origin/master' into volume-namespaces-771

Conflicts:
	flocker/node/functional/test_deploy.py
Lint fix.
Merge remote-tracking branch 'refs/remotes/origin/volume-namespaces-771' into volume-cloning-739
Sketch of design.