fix #3134 vSphere UI host create/edit requires some fixes

fix issue [#3134](http://projects.theforeman.org/issues/3134)

Host create/edit mode:
* Editing of existing VMs is not yet supported, networks and storage should by grayed out by now
* The new network interface type selection does not detect already configured values
* The thick/thin provisioning checkbox should not always be on
* If cloning a VM, the Virtual Machine options should be identical as source VM and editable (not grayed out)