Add OWL2.1 and OSPD4.1 lexicons.

These are identical to OWL2 and OSPD4, respectively, except for the
addition of four words:

GEOCACHE
GEOCACHED
GEOCACHES
GEOCACHING
Allow Zyzzyva to be branded for NSSC.
Bump version to 2.2.3.
Update CHANGES for 2.2.3.