Fix for smart manager requests queueing up

Make ajax call only when previous one completes, for cpu and network
widgets
Clear timeouts and abort jqhrx on cleanup
Widget modifications for more efficient data queries

In progress...
Set timer to get server time
Modify cpu widget to use timestamps in data urls
Modify graph rendering to use d3
Cpu graph with update transitions
CPU grpah modifications to use timestamps

Delay first fetch by server time-30 sec
Display graph title
use same update timestamp for cpu metrics of all cpus collected at once.
Modify Widget api calls to use timestamps

Display individual cpu utilization as bars
Handle resize action
Change widget data urls to use timestamps

Modify network widget to use timestamps in data urls
Network utilization widget

Fix bug in dataBuffer update
Remove log statements
Modify widgets to use timestamps for data urls

Modify memory widget and disk utilizatio widget to use timestamps in
data urls
Add indexes and reset migrations

Reset migrations - create new datastore.in and smartdb.in files
Add indexes to smart_manager tables that use timestamps
Add method to calculate avg cpu usage
Removed log statement
Merge pull request #305 from sujeetsr/issue#297_smart_manager_perf

Fix for smart manager requests queueing up