Replace liftM with <$>

Signed-off-by: Stian Ellingsen    <stian@plaimi.net>
Signed-off-by: Alexander Berntsen <alexander@plaimi.net>
Reviewed-by:   Alexander Berntsen <alexander@plaimi.net>
Simplify maybeParam using <$>

Signed-off-by: Stian Ellingsen    <stian@plaimi.net>
Signed-off-by: Alexander Berntsen <alexander@plaimi.net>
Reviewed-by:   Alexander Berntsen <alexander@plaimi.net>