Adding language, extensions and comments supports

This requests adds:

* Line and Block comments for PHP and C++.
* New .jsx file extension for JavaScript.
* Re-added the Haxe mode.

To add comments for PHP I had to add a new clike mode, since the inner most mode of PHP is clike and needed that to be registered as a mode. I would like it for a better way to add them, but didn't found it.