Add Upstream Challenge to slide-deck.
Merge pull request #31 from razvand/master

Update legal page (English & Romanian)
Add a web client for irc on rosedu.org/irc.
Add link to rosedu.org/irc to main pages (en+ro).
Add Upstream Challenge to the activities page of site.
Change events order in slide-deck.
Change rosedu/irc sidebar with one describing IRC.