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
Use ConvertsMarkdownToHTML from Sinatra::MarkdownHelper

ConvertsMarkdownToHTML already performs convertion and sanitation like
#md helper does. Less duplication feels good.
Merge pull request #848 from DimaD/fix-clojure-formatting-in-comments

Fix clojure formatting in comments