Support ImportQualifiedPost

[cblp]

Starting from GHC 8.10, with this extension enabled, one can write:

import A qualified
import B
import C

Now we can save 10 spaces on non-qualified imports!

module Bad where

import Control.Applicative ((<$>))
import System.Directory    (doesFileExist)

import Data.Map            (Map, keys, (!))
import Data.Map            qualified as M

[EncodePanda]

Yes, we need that as well at work :)
Stylish-haskell must first switch to a new parser library (from haskell-src-ext to ghc-lib-parser) in order for us to provide this feature.

[cblp]

HLint can tell a success story about such transition.

[EncodePanda]

HLint is a good inspiration :)

[jaspervdj]

This should be fixed by #307.

[cblp]

cool!