Add a method of creating a backup stack in the DB

This is a temporary storage place for resources that are going to be
deleted once their replacements are created. They must be moved out of
the stack in order to avoid conflicting with the replacement resource.

Change-Id: I081498f4c8732f893dc0d0677cf2b3f40f56d808
Pass owner_id to stack_get_by_name()

The heat.db.sqlalchemy.api supports this parameters, but heat.db.api did
not.

Change-Id: Ic805dcf6c8afdbe9e667c55d9c3b6864a76ce19a
Store the backup stack during updates

Change-Id: I64e19b0117c98eced4308727594b77e938d7ee4c
Merge "Add a method of creating a backup stack in the DB"
Merge "Pass owner_id to stack_get_by_name()"
Merge "Store the backup stack during updates"