make Haskell setup more explicit #836
:space_invader: Fix spacing of Clojure code

This commit:

  * Changes Loofah to use a HTML rather than an XML scrubber
  * Temporarily changes Gemfile to use a fork of Rouge that emits valid HTML
  * Makes some minor CSS changes to accomodate the newly valid HTML
  * Fixes #821

Once / if the pull request to Rouge is accepted the Gemfile should be
reverted to use the official version.
Merge pull request #837 from etrepum/haskell-setup

make Haskell setup more explicit #836
Merge pull request #838 from rsslldnphy/fix/clojure-whitespace

Fix spacing of Clojure code
haskell bob add more edge cases #830
Merge pull request #840 from etrepum/haskell-exercises

haskell bob add more edge cases #830
Update rouge to point to jayferd/master. Fixes #842
Fix test expectations against new rouge output
Show nit count on submission page. Fixes #812
Explain PATH. Fixes #834 (I hope)
slightly better random who-to-nitpick nitpick suggestions
Merge pull request #843 from martndemus/better-random-nitpick-suggestion

Slightly better random who-to-nitpick nitpick suggestions
Grains: for bonus points
Merge pull request #845 from henrik/grains-bonus

Grains: for bonus points
Add id to submission response
Merge pull request #847 from Tonkpils/submission-response

Add id to submission response
Rename variables in anagram example
Add test for the case with broken formatting of clojure code after run through `ConvertsMarkdownToHTML`
Use %q{} instead of %Q{} in ConvertsMarkdownToHTML tests to avoid escaping quotation marks
Fix formatting of clojure code in HTML run through ConvertsMarkdownToHTML

  * Use Loofah::fragment instad of Loofah::xml_fragment as covered in issue #821