Revert "Revert "CM11 Themes: Store hash codes for target and overlay in idmap""

This reverts commit 0d029c4619eea6da07ed22ffd5463ae73a636d8e.

Change-Id: I56531d2971c98e4b54a4a754c50d381e7b0c4587
Merge "Revert "Revert "CM11 Themes: Store hash codes for target and overlay in idmap""" into kitkat