heat tools : openstack script fixes for grizzly

Update tools/openstack so it works with the grizzly preview repo
(tested on F18 with both grizzly repo and folsom distro packages)

fixes bug #1164605

Change-Id: I347a53c9be677131dad37f9fbeb1ed5eb9cb810b
heat : cloudwatch paste.ini credentials incorrect

The cloudwatch paste config should specify service/heat
like the other API services, not admin/admin

Change-Id: I0590c88edd6b544aba467ab171dd7f610b50c380