Updating Heat stack and switch from boto to python-heatclient

Hi,

This patch replaces the 'boto' lib with 'python-heatclient'. For that you **need** to change the keystone auth_url in `heat/client.py` (I will move it to config soon).

Also we not longer use the EC2 credentials, so the heat_user and heat_password are the OS credentials, not EC2 (!)

EDIT: Please check the `heat/client.py` especially the 'heat_opts' section on top and edit that as you need ;-) 

All other operations should works normally.