changed google calendar url to new calendar
changed logic for upcoming and past events
connect buttons inherit color, hopefully don't have to change these every time a section is added
added Event.upcoming and Event.past class methods
added event section to home page.  set to update every 5 minutes
got rid of update_calendar rake task, not needed (updates done in controller every 5 minutes)
allow strong, a, and i elements in event descriptions
Merge branch 'feature/events' into develop