Add Heat's API v1.0 initial documentation

This patch adds the initial documention for Heat.  This documentation
is sourced from:

https://github.com/openstack/heat/tree/master/doc/docbkx/api-ref/src/
   wadls/heat-api/src

Change-Id: Ifbfd6d3609c2e2fac51c60d7be34be50f2339911
Corrected errors in Identity v2.0 wadls

Change-Id: I64104c0d2c683bd4ea746556f7036da05becea0a
author: diane fleming
Merge "Add Heat's API v1.0 initial documentation"
Merge "Corrected errors in Identity v2.0 wadls"