Description of problem:
Start nagios as part of auto discovery script if it was not already started.

Version-Release number of selected component (if applicable):
nagios-server-addons-0.1.5-1.el6rhs.noarch

How reproducible:
Always.

Steps to Reproduce:
1. Install Nagios on RHS nodes.
2. Stop nagios server by running the command 'service nagios stop'
3. Now run the auto discovery script. 


Actual results:
Auto discovery script will display a message saying Cluster configurations synced successfully from host <IP-address-of-RHS-server>
'Start the Nagios service to monitor'

Expected results:
Instead of explicitly asking the user to start nagios, discovery.py should be able to start it automatically if it was not already started.

Additional info: