[cadcdev-tiki] Dreamcast mouse support

[Sam S. <sam...@gm...>]

I checked in a few updates to Tiki:

* dc/src/plathid.cpp: Support the Dreamcast mouse
* dc/TikiTest/src/test.cpp: Draw up to four pretty mouse pointers,  
change the direction the sphere rotate on mouse click, and display  
the names of devices as they attach and detach.

-Sam