Remove unnecessary methods from Data.Map.Strict.
Remove unnecessary methods from Data.Map.Strict.

Remove implementations of mapKeys and mapKeysMonotonic
from Data.Map.Strict module. These methods modify keys only
and even Data.Map.Lazy are strict in keys.

hvr/containers,Zigazou/containers,hvr/containers,Zigazou/containers,Zigazou/containers,ekmett/containers,shockkolate/containers,meiersi/psqueues-old,shockkolate/containers,shockkolate/containers,iu-parfunc/containers,hvr/containers,ekmett/containers,iu-parfunc/containers,ekmett/containers,iu-parfunc/containers