Removed all things Share.js

Why? These are some of the reasons:
 - After some experiments, I realized that Share.js can't be used as a
   standalone thing. It needs to have a Node.js server behind.
 - I can't learn Node.js now, I just don't have the time.
Removed old Etherpad code

In the process of doing that, I have also added the jQuery adapter of
CKEditor. This is useful for accessing the user input.

I have also included a small snippet of code that calls console.log on
user input every 0.5 seconds. Just as a test.