varous fixes/extensions to games/^(4s 5s):
 - be (more) responsive (to keyboard and reshape) in paused state
   (during blinking, between drop and appearance of next brick)
 - q/Q always quits (also in suspended state)
   (previously, to quit in suspended state you needed two q's:
    one to switch to non-suspended state, after which next
    one would quit)
 - also Del always quits
 - also p/P enables suspended state
 - moving mouse cursor out of resp. into playing field
   enables resp. disables suspended state
 - visual indication of suspended state (faded color, mouse cursor)
 - replace explicit flushing of channels by having a separate
   process that only passes on key events in non-suspended state,
   and keep mouse and 'previous mouse' info always up-to-date,
   to avoid the case where a late mouse click to lower one brick
   somehow gets 'delayed' and causes instantanious drop of the
   subsequent one, as soon as it appears after the pause
 - tweaked mouse warping a bit more.
   now also warp when leaving suspended mode.
   the hope is that by warping the mouse (horizontally)
   we can always keep it within the bounds of the board.
   previously, it might happen that the brick would be
   at the far right, and the mouse cursor at the far left,
   such that it would not be possible to move the mouse far
   enough left to move the brick entirely to the left.

Axel.