Make GetProperty more clear

Change-Id: I23ba7950364fa402f1337e8557c3cf8cd9c810cc
more consistent code style in drawingml export

Change-Id: Iba6670fbeb064ee1b1ee54a96267f660c86e18f2
Use Any.get<T>(..) instead of Any.getValue(..) and ugly cast

Change-Id: I1c76ee7c7873e76fb1682475141c14dd658bff4a
SAL_WARN_IF

Change-Id: Ic2644f8a0f2f1479779aef2d6b0886604c139acb