Partial-Bug: #1399792 - Introduces Passenger on top of Apache for Centos6.4

This check-in also:

- Enhances setup script to also handle upgrade of contrail server manager packages, in addition to fresh install
- Spec file changes make sure config files are not overwritten in case of upgrade of Contrail Smgr package
- Brings in depepdent packages for Passenger as sever manager dependencies
- If domain name is given as an option, it is put into cobbler settins file
- /etc/resolv.conf is modified if Localhost IP and 8.8.8.8 are missing. These are added to make sure the apt repos are reachable

Change-Id: I35fe6371f15242ac391aa584aab7dc4c55343c30