Improve markup gems to prevent 500 errors
Created by: Razer6
What does this MR do?
This PR add support mor missing markup-gems required by github-markdown. Gem versions are taken from https://github.com/github/markup/blob/master/Gemfile.
Additional, this PR disables markup for pod files, because an external tool is required (perl).
Why was this MR needed?
Currently, when accessing a (textile, mediawiki, creole)-file a 500 error is raised, because of missing gems.
What are the relevant issue numbers / Feature requests?
This PR fixes following issues: