The following changes have been made to this directory since R3:

     o	utilities for writing extensions added.
     o  SHAPE extension added.
     o  MIT-SHM (shared memory pixmaps) extension added.
     o  Multi-Buffering extension added.
     o  Input extension added (new devices, not synthesis).
     o  MIT-SUNDRY-NONSTANDARD (various MIT hacks) extension added.
