Can not suspend or resume anymore when failed

[huangtianhua]

1. create a stack with nova server
2. suspend the stack, failed due to some reasons, the stack went to 'SUSPEND_FAILED' state, and the resource(nova server) went to 'SUSPEND_FAILED' state
3. then we can't suspend the stack anymore, because the resource(nova server) status is not COMPLETE:
   def suspend(self):
        '''
        Suspend the resource. Subclasses should provide a handle_suspend()
        method to implement suspend
        '''
        action = self.SUSPEND

        # Don't try to suspend the resource unless it's in a stable state
        if (self.action == self.DELETE or self.status != self.COMPLETE):
            exc = exception.Error(_('State %s invalid for suspend')
                                  % six.text_type(self.state))
            raise exception.ResourceFailure(exc, self, action)

         .... (DO SUSPEND)

4. stack resume has the same problem.
    May be the state check for suspend should be:
          if (self.action == self.DELETE or (self.acton != self.SUSPEND and self.status != self.COMPLETE)):
            exc = exception.Error(_('State %s invalid for suspend')
                                  % six.text_type(self.state))
            raise exception.ResourceFailure(exc, self, action)
          .... (DO SUSPEND)

    the state check for resume should be:
         if self.state not in ((self.SUSPEND, self.COMPLETE), (self.RESUME, self.FAILED)):
            exc = exception.Error(_('State %s invalid for resume')
                                  % six.text_type(self.state))
            raise exception.ResourceFailure(exc, self, action)
         ...... (DO RESUME)