whether the template is using the JSON or YAML format

[huangtianhua]

My operations as:

1. make a file, but only written some string such as "hello test" in it, it's obvious not JSON or YAML format.

2. use template-validate api to validate the file.

3. an error is raised: "The server could not comply with the request since\r\nit is either malformed or otherwise incorrect."

4. because an unexpected exception raised in default_for_missing():
   "TypeError:'unicode' object does not support item assignment"

5. I think it's a bug, at least we should catch the exception and raise the correct error message such as "invalid format" and to tell the template is not using the JSON or YAML format.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/65644

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/67396

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/67396
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=dbc66c1efdd0504dad47f03203794039287d4a9f
Submitter: Jenkins
Branch: master

commit dbc66c1efdd0504dad47f03203794039287d4a9f
Author: huangtianhua <email address hidden>
Date: Fri Jan 17 16:00:33 2014 +0800

    Fixes template not using the JSON or YAML format

    An internal unexpected exception is raised while validating a template
    which only has string content. We should handle the case and raise the
    correct error message such as "invalid format" and to tell the template is
    not using the JSON or YAML format.

    And modify incorrect version name and version date in this patch.
    And change "template" from global variale to class varialbe in
    test_api_cfn_v1.py. (missed in another patch which this patch
    depends on: Change Idc2ba2b9 by misoperation)

    Change-Id: I46ee8c48e3ddae71be061cfda0c029d86d132684
    Closes-Bug: #1267379