Play Framework

Added mkv in mime-type
Added new hook to allow plugin to take controller during the RenderTemplate phase (which means we can do interesting things like using another template engine without much effort), or renderXML if the request header is set to xml for example).
Give a change to call the renderTemplate from the plugin from the controller.
Fixed the build.xml to compile the test-runner. Need to check if it was modified to not compile it if not needed.