"Simplify" static method imports

[rahulmutt]

Currently, static method imports give you multiple options:

foreign import java unsafe "@new" newFile  :: String -> Java a File
foreign import java unsafe "@new" newFile1 :: String -> IO File

It would be great to unify this to:

foreign import java unsafe "@new" newFile  :: (MonadIO m) => String -> m File

The main requirement for this is that MonadIO should be in the standard library.

Con:
Makes it harder for beginners and increases the learning curve.