The staticmethod member_error_handler is handing the default member
related failures that can occur for modules with member support.
This can simply be enabled with fail_on_member_errors=True for
execute_ipa_commands.

An exception handler is also now usable with execute_ipa_commands. In
addition to the the exception it is also getting the same user defined
arguments that the result_handler is getting.

handle_result has been renamed in result_handler and handle_result_user_args
has been renamed to handlers_user_args.

Additionally the errors list does not need to be defined in the module.
The method execute_ipa_commands is doing this internally and is also
adding error: error to handlers_user_args if the handler is having errors
in the argspec and errors is not yet set in handlers_user_args.

Tests have been added to make sure that no user args for the handler
have been set without an own result or exception handler. Also the use of
fail_on_member_errors together with a result_andler is leading to an
error.