Several editors on the same page

This will allow to have several editors on the same page, plus will allow to edit an issue and comment at the same time. Ref #318

![screenshot_1](https://f.cloud.github.com/assets/3051676/2490311/e72f22c0-b1a1-11e3-9ad0-66c505aafdf9.png)

@elkuku now it is ok? ;)