Bootstrap v3.1.1 & LESS Improvements

Hmm... well, all is in the title. :smile: 

* Prefer import Bootstrap LESS to use Bootstrap variables & mixins
* Fixes some incoherences in CSS, e.g:
![sdsdfg](https://f.cloud.github.com/assets/846943/2180283/30e2669c-970e-11e3-88f5-a43a87b7688f.PNG)
* Updates, updates...

Also [fix](https://github.com/LeoColomb/daux.io/compare#diff-61) no PHP output.