P3:Changes to provisioning modules to enable vcenter and esxi(complete) provisioning. Adding 2 new tasks 'prov_vcenter' and 'prov_esxi_computevm', along with a  new example testbed file 'testbed_vcenter_esxi'. The earlier mode of 'esxi' only is untouched. Additional helper tasks have been added in vmware.py to gather testbed information and provision. esxi_prov.py has been borrowed from 'server-manager' scripts. No modifications have been done to that script, as in the current state it works as expected.

Change-Id: I0c1f37190ce0f1607ef955a85a22729daac5cb79
Merge "P3:Changes to provisioning modules to enable vcenter and esxi(complete) provisioning. Adding 2 new tasks 'prov_vcenter' and 'prov_esxi_computevm', along with a  new example testbed file 'testbed_vcenter_esxi'. The earlier mode of 'esxi' only is untouched. Additional helper tasks have been added in vmware.py to gather testbed information and provision. esxi_prov.py has been borrowed from 'server-manager' scripts. No modifications have been done to that script, as in the current state it works as expected."