Xnest was half-using midispcur and doing a bad job of it. Replace all of
that code with mipointer which does a lot of the work.
Support DDXen which don't provide GetWindowPixmap, or which return NULL for
the root pixmap.
Replace miSprite implementation with Damage-based one. Otherwise damage and
misprite conflict causing looping.
Change pScreen usage around a bit to eliminate warnings
Move extern function declarations to window.h
Cleaned up code since client's saveSet is no longer defined as a pointer*
Added externs back in
Change #if to #ifdef to fix compiler warning
Add function declarations that were inadvertently removed by previous check
in
Disable extensions that are not (yet) supported by DMX
