Bug 929968 - [Keyboard] adding BÉPO french layout

[https://bugzilla.mozilla.org/show_bug.cgi?id=929968](https://bugzilla.mozilla.org/show_bug.cgi?id=929968)
![2013-10-29-194118_1920x1080_scrot](https://f.cloud.github.com/assets/914451/1431330/d105be0a-40cc-11e3-9423-e00cc19e1da3.png)