Client Side Changes for Security Groups Support.

- Added new secgroups command with the following options
  - list
  - get
  - add_rule
  - delete_rule
- Added corresponding calls into the REST API

Implements blueprint: security-groups

Change-Id: Ie6d4bc2ce31dc18f172e92efa46ccdeea3e0a22a
Merge "Client Side Changes for Security Groups Support."