Outsourced TinyMCE

* Add tinymce/tinymce as requirement to composer.json
* Move TinyMCE languages to own directory
* Update language file handling to check for existing default territory expansion
* Remove embedded TinyMCE

Similar to how [MopaBootstrapBundle](http://github.com/phiamo/MopaBootstrapBundle) handles this:
* Add symlink and mirror commands for external TinyMCE
* Add symlink and mirror script handler for composer