feat(mixit15):
- Created 2015 event,
- home page cleanup,
- hide menus (sessions, planning, members, speakers,... all pointing on CURRENT event),
- added info menu for 2014,
- updated sponsors documents links
typo
Merge pull request #305 from mpetitdant/fix/304-home-for-2015

feat(mixit15): Go for 2015 !