Update smartdb model for disk utilization. Update the relevant model fields
from IntegerField to FloatField to match the values computed. Add the south
migration file for it. Add serializer for disk utilization.
Compute disk utilization information from /proc/diskstats. Add logging to the
proc retreiver.
Add API support for disk utilization statistics. Support query
parameters: limit=x returns upto x latest statistics. t1=x&t2=y returns
statistics between t1 and t2. t1 and t2 are timestamp strings deserialized from
django DateTimeField.
Update CLI to retreive disk utilization statistics.
Update setuptools_source url to get the latest setuptools for buildout to work
properly.
Merge branch 'issue#113_backend' of https://github.com/schakrava/rockstor-core into disk_utilization
Modified data format

Modified sample data format to match that returned by server