Sidebar sections linking to upcoming and past academic events updated; 78 events linked to so far

I have updated the sidebar section "Upcoming academic events", which now counts 10 future events, and updated and renamed the section now called "Past events (2012-2014)". The latter now counts 43 events in which I have played one role or another.

The section "Past events (-2011)" counts 25 events. Total number of events linked to to date is thus 78.