Add strict ver. of (<$>): (<$!>) to Control.Monad

A strict (<$>) has been proposed numerous times. The first time
around[1] by Johan Tibell, and the last time around[2] by David
Luposchainsky. David's thread was able to avoid The Bikeshed Monster,
and his (<$!>) proposal received unanimous +1s all around.

This addresses #9099.

 [1]: http://www.haskell.org/pipermail/libraries/2013-November/021728.html
 [2]: http://www.haskell.org/pipermail/libraries/2014-April/022864.html

Authored-by: Alexander Berntsen <alexander@plaimi.net>
Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>