Big import of updated joystick code from PLIB, with permission from

Big import of updated joystick code from PLIB, with permission from
Steve Baker.  Most of the adaptation done by John, with a little bit
of testing and changes by Thierry Thomas and myself.  Seems to compile on:

  WIN32
  Red Hat LINUX
  FreeBSD
  NetBSD/amd64

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@450 7f0cb862-5218-0410-a997-914c9d46530a