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

Conflicts:
        CHANGELOG.md
        metadata.rb
        spec/spec_helper.rb

Closes-Bug: #1351619
Change-Id: Ie67e84e5695bd5f9ceaa6ed6682cfe33f7ed0b68
(cherry picked from commit 4529146a83cc4f5d1ec8c5c0f5cbf5346a05b022)