varregion: remove --noterrain and --noparcel parameters in 'load oar'.
Add --forceterrain and --forceparcel to 'load oar'. In order to not change
the operation of --merge (which does an object merge and suppresses terrain
and parcel information loading), added the --force* parameters to be used
when loading multiple oars to build up a varregion.

Added --rotation and --rotationcenter parameters to 'load oar' which apply a rotation to
the loaded oar objects before displacing. The rotation is in degrees (pos or neg)
and the center defaults to "<128, 128, 0>".