Adds vmware ESXi hypervisor support.

 * supports nova VMwareESXDriver and VMwareVCDriver.
 * new parameter 'hypervisor_type'.
 * vmware related parameters:
   - 'vmware_host'
   - 'vmware_user'
   - 'vmware_pass'
 * adds support into 'openstack_system' script. (nzaporozhets@mirantis.com)
 * site_openstack_ha_compact.pp example modified.
Support nagios master deployment

  * adds nagios-master support to astte
  * fix necessary packages for nagios-master
  * adds nagios in examples
Some additions for scenario 2

 * adds example in config.yaml
 * fix for cobbler_system.py
 * installation of "python-pyvmwareapi" rpm on fuel node