sort sessions list by date
fix issue where controllers got instanciated twice

They were instanciated once from the route definition, and a second time
within the html.
improve display of sessions
split main.js in menu.js and footer.js
add new files in the middle of work
major rework of site navigation based on angular routing

Previously, each main section (address, sponsors...etc.) were a page.
This forced the reloading of the entire site, instanciations of
controllers...etc.

Rework entirely so that only index is loaded as a page, and then
everything else is a template managed by angular.

Improve texts internationalisation on client side.

Moreover, take the oportunity to clean.
add a submenu with list of sessions

Note: should make it work with:
- bootstrap scrollspy
- angular $anchorScroll
update text internationalisation
add FullCalendar jquery-ui plugin
replace google calendar by jquery-ui fullcalendar

Easily usable thanks to angular-ui
implement password edition
initialise database default user through cassandra-cli

Remove database initialisation done from code.
hide speakers page
update google map key, add meta tags
update favicon
fix spelling mistake