Markdown Support

Added markdownsupport with new Editor (http://toopay.github.io/bootstrap-markdown/) (removed old one)
New Editor ist testable via Selenium.
Old Cards will not be displayed the right way and no migrationmechanism is included.
LaTeX should still work.

see http://thmcardsk3.cloudcontrolled.com/

After merging revert changes to travis.yml