heat engine : LoadBalancer resource delete nested stack

Ensure LoadBalancer resource deletes the underlying nested
stack when the owning stack is deleted - needs to inherit
from stack.NestedStack as this implements handle_delete()

fixes bug 1097394

Change-Id: I2002bed361511a495cbdf38cad7b61e148a68ba2
Signed-off-by: Steven Hardy <shardy@redhat.com>
heat engine : DBInstance don't pass credentials to cfn-init

Don't create user/accesskey and pass them to cfn-init as resource
metadata for internal nested stacks is not available via the cfn API
so passing them causes an error in the engine logs (and creates some
unnecessary keystone credentials)

fixes bug 1097362

Change-Id: If2fe484d834e3e5730b21a18c363a5bf5a4c45f6
Signed-off-by: Steven Hardy <shardy@redhat.com>
Merge "heat engine : LoadBalancer resource delete nested stack"