* Adds support for more than one controller. Previously more than
      one controller was initialized and the docs said they worked, but
      only one was actually read.                                      
    * Removes unnecessary detection on initialization. This allows the
      module to be initialized without controllers plugged in (hot    
      swapping controllers works). This removes a warning if the user
      has an unrecognized controller plugged in, but the only        
      unrecognized controller I have been able to find information about
      online is the PSX mouse, which I've never actually seen.          
    * Adds a GC_DDR option value to have direction presses register as
      buttons instead of axes. Allows the module to be used for Dance
      Dance Revolution emulators like Stepmania.                     
    * Adds psx_* to documentation.   

Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>