* upgrade to bootstrap 3.3.6
* new Header, port website LESS
- Add the new header
- Modify sub-header in order to handle “back” button and version
switcher
- Port website’s Less:
* Use same variables’ names
* Review fonts and colours in order to fit the new style
* add new footer
* Review and optimise JS code in order properly handle the new header,
footer and card.top animations
* replace banner images
