You all know that it's uppercase I

Define a small overlay on top of gfm that highlight `iPython` in red.

On **hover** with pure css, those red `iPython` will show : "I'ts uppercase I, IPython."
Shown only on markdown **Edit** of course. Zero influence on nbviewer or other export. 
No interference with the parsing of markdown as it is a markdown **overlay**.





![capture decran 2014-02-23 a 23 59 31](https://f.cloud.github.com/assets/335567/2241703/6054f6e4-9cde-11e3-87b8-422804bfbc20.png)