Description of problem:
Remove disk when use name instead of id, throw exception

Version-Release number of selected component (if applicable):
av9.6

How reproducible:
Always

Steps to Reproduce:
1. Create some disk with alias = test_disk
2. Run via rhevm-shell remove disk "test_disk"
3.

Actual results:
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/cli/context.py", line 191, in execute_string
    self._execute_command(command)
  File "/usr/lib/python2.6/site-packages/cli/context.py", line 411, in _execute_command
    command.run(self)
  File "/usr/lib/python2.6/site-packages/cli/command/command.py", line 101, in run
    self.execute()
  File "/usr/lib/python2.6/site-packages/ovirtcli/command/remove.py", line 149, in execute
    context_variants=typs[args[0]]
  File "/usr/lib/python2.6/site-packages/ovirtcli/command/command.py", line 357, in get_object
    return self.__get_by_name(coll, obj_id, kwargs)
  File "/usr/lib/python2.6/site-packages/ovirtcli/command/command.py", line 371, in __get_by_name
    return coll.get(name=name)
TypeError: get() got an unexpected keyword argument 'name'


Expected results:
Some error message: "Impossible to remove disk by alias, please use disk id"

Additional info: