Remove the dependency of login information on worker nodes for vsphere cloud provider:
1. VM Name is required to be set in the cloud provider configuration file.
2. Remove the requirement of login for Instance functions when querying local node information.
The url which is used for communicating with govmomi should not include
port number. A port number other than 443 will result in 404 error.
VCenterPort stays in VSphereConfig structure for backward compatibility.
addressed review comments
Addressed review comment for pv_reclaimpolicy.go to verify content of the volume
addressed 2nd round of review comments
addressed 3rd round of review comments from jeffvance
