cyclades: Additional vm task state mappings

The mappings are related to the volumes api vm tasks.

Refs #98
astakos: Fix system project display in usage view

Identify system projects using project's system_project attribute.

Refs #98
ui: Volumes ui integration

- Volume api model and collection objects
- Volumes list pane
- Volume create wizard
- VM volume list in icon/single view
- Move snapshot functionality from vms to volumes entries

Closes #98