Resolve HLint warnings

All warnings are either fixed or, if more appropriate, HLint is
configured to ignore them. HLint suggestions remain.

  * Ignore "Use camelCase" warnings in Lua and legacy code
  * Fix or ignore remaining HLint warnings
  * Remove redundant brackets
  * Remove redundant `return`s
  * Remove redundant as-pattern
  * Fuse mapM_/map
  * Use `.` to shorten code
  * Remove redundant `fmap`
  * Remove unused LANGUAGE pragmas
  * Hoist `not` in Text.Pandoc.App
  * Use fewer imports for `Text.DocTemplates`
  * Remove redundant `do`s
  * Remove redundant `$`s
  * Jira reader: remove unnecessary parentheses

1 files changed, 0 insertions, 2 deletions

diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 933798534..c03a99cdb 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -1,12 +1,10 @@
 {-# LANGUAGE NoImplicitPrelude     #-}
 {-# LANGUAGE CPP                   #-}
-{-# LANGUAGE DeriveDataTypeable    #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE ScopedTypeVariables   #-}
 {-# LANGUAGE ViewPatterns          #-}
 {-# LANGUAGE FlexibleInstances     #-}
-{-# LANGUAGE TypeSynonymInstances  #-}
 {-# LANGUAGE LambdaCase            #-}
 {-# LANGUAGE OverloadedStrings     #-}
 {- |