Configuring with "--enable-warnings" broke three demos:

Configuring with "--enable-warnings" broke three demos:
 * CallbackMaker defined, but did not use, the Joystick() function
   (a callback for the freeglut joystick interface).  I uncommented
   the callback-registration.  I assume that it was commented out
   because it was spammy.  (freeglut does joysticks by polling with a
   timer.)  Perhaps a longer interval than 10ms would be advisable?

 * fractals.c used strcpy() without getting the prototype.  Added
   #include <string.h> at the top.

 * fractals_random.c had the same problem as fractals.c.

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@415 7f0cb862-5218-0410-a997-914c9d46530a