patch applied (ghc): fix possible ^C problems

[Simon Marlow]

Thu Jun  8 07:44:57 PDT 2006  Simon Marlow <simonmar at microsoft.com>
  * fix possible ^C problems
  Calling prodAllCapabilities() from interruptStgRts() was wrong, for
  the same reasons that we stopped doing it in handle_tick().  We now
  use the same mechanism (send a byte down the pipe to the IO manager
  thread), but abstract it in a wakeUpRts() function in the scheduler.

    M ./rts/Schedule.c -1 +30
    M ./rts/Schedule.h +6
    M ./rts/Timer.c -13 +1