WIP: Upgrading to TinyMCE 4.0.1.

#6251 
For now we have TinyMCE 4.0.1 out of the box. There is still some things to fix.
![selection_066](https://cloud.githubusercontent.com/assets/1222368/3351082/edd4ae80-f9f2-11e3-941e-3303cbffbe71.png)