Activities should be expandable/collapsable

[seejee]

A few questions:

• What information do you want to be displayed when an activity is collapsed?
  • Participate button?
  • Author?
• Do you want activities expanded or collapsed by default?
• Do you want "Expand All" "Collapse All" buttons?

[practicingruby]

The participate button is a tricky question because ideally, you'd want to see what you are participating in at a glance, but not be able to click participate if you're not already a participant (as you'd want to see the whole description). Still, we don't want to make the button appear or disappear based on whether you're a participant, nor would we want to disable it or anything weird like that. I suppose show it for now and we'll see how that goes.

Try hiding the author and collapsing by default. I'm not entirely sure this is going to be a good feature overall, but we can give it a try.