Un-mock heat and remaining mocked calls

This also updates Stack.resources to deal with the nested
stacks introduced by the updated tuskar-api.  The tests
should eventually be updated to include nested stacks.

There are some new Plan properties that have 'todos'
indicating that they will be updated once the tuskar-api
pythonclient is updated.  Testing was done with hardcoded
values there.

Change-Id: I8ba071bf586bb2350ed4838a9cf9199f195cbe17