Rebase onto master
Modularisation of markup engines
   * if a JBake supported engine is not found on classpath, we must skip it too
Modularisation of markup engines
   * if a JBake supported engine is not found on classpath, we must skip it too
   * added an ErrorEngine so that the user gets nice error message on rendered page
Fixed hardcoded file extensions in FileUtil
Merge pull request #67 from melix/parser-modularization

Parser modularization