Support VMware hypervisor inspector

1. If the compute driver is vmwareapi.VMwareESXDriver or
vmwareapi.VMwareVCDriver, set the hypervisor_inspector to vsphere and
add vmware section in conf file.
2. Reuse the vmware related attribute from compute cookbooks since
ceilometer need monitor the same vsphere.
3. Update the testcases

Closes-Bug: #1351619
Change-Id: Ie67e84e5695bd5f9ceaa6ed6682cfe33f7ed0b68