Add ceilometerclient and bootstrap-datepicker as dependency.

Add python-ceilometerclient to the requirements.txt file
since ceilometer api depends on it.
Add bootstrap-datepicker to select date.

Implements bp ceilometer.

Change-Id: Ifd9c9240c770bea3304dae83d6abc79e7580a234
Add ceilometer api and the tests for it.

Implements bp ceilometer.

Change-Id: I5b3392de8bae2be8cbcba7a580af669676e54052
Add metering panel to admin console.

Now it has usage tables for disk usage,
network traffic usage, network(quantum) usage,
objectstore usage and stat charts.

Implements bp ceilometer.

Change-Id: I9e6c2d25c2587a7642271e43109bc67e2ea1726f