Migrating from bootstrap to foundation 5

- Removed `askbot/media/bootstrap/` folder and old jquery and modernizr filesi.
- Added bower.json file with foundation latest dependencies.
- Installed foundation anf his dependencies with bower
- Templates have been modified to call jquery, fastclick, modernizr, and foundation
  instead of old removed files.

Now some old bootstrap classes ain't recognized in the style.css file see:<https://gist.github.com/BenjaminABEL/246925471ad9caef8af0>, and much more work is needed(utils.js, and maybe more).