Comment 4 for bug 1472515

Reviewed: https://review.openstack.org/199918
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=18ded430d0e256ce5f9eec3ef61b5337596f914a
Submitter: Jenkins
Branch: master

commit 18ded430d0e256ce5f9eec3ef61b5337596f914a
Author: huangtianhua <email address hidden>
Date: Thu Jul 9 09:15:10 2015 +0800

    Return error message if validate fail when clearing hook

    There are some situations:
    1. User can run the command "heat hook-clear" on any
    resource in the stack, even if there is no hook
    defined on it, and no error or warning message is returned.
    2. User run the command "heat hook-clear" on resource
    to clear the hook which resource unset, and no error or
    warning message is returned.
    3. User run the command "heat hook-clear" on resource
    even if the resource's action is not support to signal, and
    no error or warning message is returned.
    4. User run the command "heat hook-clear" to clear invalid
    hooks, and no error or warnning message is returned.

    This patch will check the situations above before call
    resource.signal, and will return error messages to user.

    Change-Id: Ifb9befad864ebe1bb5f8b419b95d1b3a95530573
    Closes-Bug: #1472515