Add clean configuration files to upgrade from H to I

Any new configurations for Icehouse should go in one of the upgrade files in
from-havana directory.
Also moves {BASE,TARGET}_RELEASE vars forward to Havana->Icehouse pair.

Change-Id: Iac520a8de4c3b9f14e2289cfb9b6a50c4ab0ce32
Merge "Add clean configuration files to upgrade from H to I"