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  What @chessbyte is suggesting is to re-write the method like this so it properly handle an array of IDs which makes perfect sense.
```ruby
def self.cloneable?(ids)
  VmOrTemplate.where(:id => ids).all?(&:cloneable?)
end
```
I also realized this class method does not have any tests.  We need to add a few tests to cover calling this method with multiple VMs that have different combinations of cloneable? true/false values.