[WIP] Added a new method cloneable? to check if VMs/Templates can be cloned or not

issue #253
https://bugzilla.redhat.com/show_bug.cgi?id=1122712
@AparnaKarve The ```cloneable?``` method is being called with ```vm_ids``` which implies there could be more than one.  Currently the method ```VmOrTemplate.cloneable?``` only accepts a single ID.  Does the ```cloneable?``` class method need to be modified to support multiple IDs?