patch applied (packages/base): Generalise the type of onException

[Ian Lynagh]

Sat Aug  2 17:30:01 PDT 2008  Ian Lynagh <igloo at earth.li>
  * Generalise the type of onException
  The type of the thing to do on an exception is now
      IO b
  rather than
      IO ()
  which better matches functions like bracket.

    M ./Control/Exception.hs -1 +1

View patch online:
http://darcs.haskell.org/packages/base/_darcs/patches/20080803003001-3fd76-c2a0a1f4eec580ca030ba5355140a482fbc13ce2.gz