userportal,webadmin: validation error on create template

It was not possible to create a new template. The problem was that:
- UnitVmModel.validate() did not pass the CPU validation: new
  IntegerValidation(1, behavior.maxCpus) because the behavior.maxCpus was not
  inited.
- the behavior.maxCpus was not inited because it is inited in the
  VmModelBehaviorBase.updateMaxNumOfVmCpus() which is called which is triggered
  by calling the VmModelBehaviorBase.updateNumOfSockets() which is supposed to
  be called from the specific behavior classes'
  postDataCenterWithClusterSelectedItemChanged.
- The problem was that the
  NewTemplateVmModelBehavior.postDataCenterWithClusterSelectedItemChanged
  did not called the updateNumOfSockets()

Change-Id: Ida04f94dcbe4d357f306eec60134661c43d9fcdf
Bug-Url: https://bugzilla.redhat.com/1085754
Signed-off-by: Tomas Jelinek <tjelinek@redhat.com>