Initialize resources to DELETE-COMPLETE if missing during stack delete

If the parent stack is being deleted and a given resource cannot be found in
the data store, initialize its state to DELETE:COMPLETE instead of
INIT:COMPLETE.

fixes bug 1204268

Change-Id: I5074d63928c3b39fe6ad85dc6af1d02db777acc8
Merge "Initialize resources to DELETE-COMPLETE if missing during stack delete"