In REST API JSON API body should be size limited

[Clint Byrum]

JSON costs memory and CPU to parse, so we should put a cap on the length of JSON allowed in request bodies.

A workaround for this might be to run under a proxy or even apache mod_wsgi and cap the request body length there.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44585

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44585
Committed: http://github.com/openstack/heat/commit/d899f8d9b745af7f9e7240389718bd3c8045a7dc
Submitter: Jenkins
Branch: master

commit d899f8d9b745af7f9e7240389718bd3c8045a7dc
Author: Liang Chen <email address hidden>
Date: Sat Aug 31 14:53:43 2013 +0800

    Impose a size limit on JSON request body

    The size limit on JSON request body is to ensure the server not being
    overwhelmed by extremly large JSON request body.

    Fixes bug #1215501

    Change-Id: Ia58f6690e994d34212953c44821f7a4cc4c435fe