Clear new or building backups on reset-task-status

The reset-task-status management call now also clears off
any new or building backups for the instance by marking
those backups as FAILED.

Fixes Bug # 1205471

Change-Id: I478782b5e90c9965b91169a784b2ea65bda8a8b4
Adding volume size to the backup views/models.

* Save the size of the guest before running a backup
* Display the size in the backup GET/LIST views
* Simplify the dbaas module removing redundant class.
* Switch get_filesystem_volume_stats to use os.statvfs()
* Change output of volume stats to return used in GB
  to simplify various view that display it.

Implements: Blueprint backup-volume-size

Change-Id: I860427d3491acb34e43ee23f91e4ffbb39e0042c
replication initial

moved clustertype to trove directory

removed dummy cluster api

mocking up against the flavors api instead

refactor to use real a more OO approach

adding unittest coverage

added proboscis

remove proboscis

setup maps

fix update to insert

fixed up unittests

Fix/Add docstrings

Add debug statements to controller

fixed missing import for _

add more debug logging

fixed broken string interpolation

added more debug logging

added created time to the clustertype model

added default value to clustertype migration