Include parameter name in StackValidationFailed exception

[Vijendar Komalla]

When an incorrect parameter is passed, StackValidationFailed exception would be thrown, but this exception does not include parameter name. For example, see the following exception;
{
    "message": "must begin with a letter and contain only alphanumeric characters.",
    "traceback": "Traceback (most recent call last):\n\n File \"/opt/stack/heat/heat/engine/service.py\", line 62, in wrapped\n return func(self, ctx, *args, **kwargs)\n\n File \"/opt/stack/heat/heat/engine/service.py\", line 542, in create_stack\n stack = parser.Stack(cnxt, stack_name, tmpl, env, **common_params)\n\n File \"/opt/stack/heat/heat/engine/parser.py\", line 108, in __init__\n context=context)\n\n File \"/opt/stack/heat/heat/engine/parameters.py\", line 407, in validate\n\n File \"/opt/stack/heat/heat/engine/parameters.py\", line 220, in validate\n self._validate(self.default(), context)\n\n File \"/opt/stack/heat/heat/engine/parameters.py\", line 288, in _validate\n\n File \"/opt/stack/heat/heat/engine/parameters.py\", line 159, in validate_value\n if name == \"name\":\n\n File \"/opt/stack/heat/heat/engine/constraints.py\", line 169, in validate_constraints\n raise exception.StackValidationFailed(message=six.text_type(ex))\n\nStackValidationFailed: must begin with a letter and contain only alphanumeric characters.\n",
    "type": "StackValidationFailed"
}

Including parameter name in error message would be helpful in identifying the issue quickly.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/97264

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/97264
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=7348b5303bfa7fdd31a2f8c3226a3cdf7ada9102
Submitter: Jenkins
Branch: master

commit 7348b5303bfa7fdd31a2f8c3226a3cdf7ada9102
Author: Vijendar Komalla <email address hidden>
Date: Mon Jun 2 10:13:33 2014 -0500

    Include parameter name in error message

    Including parameter name in StackValidationFailed exception
    message.

    Change-Id: I9d8f4e4a1986496d9be96f0e2a272cbc4da92b49
    Closes-Bug: #1324968