Cluster Actions

[jsha]

Right now if you do 'Block All' on a list with 10k users, you'll wind up with 10k entries on your Actions page, which makes it unreadable. Instead we should cluster similar Actions and display only a single line for them. More specifically, all Actions that have the same type, cause, cause_uid, and status should be clustered, so long as they are adjacent in time. They should include a count of the number of Actions clustered on that line.

[doeg]

This can probably be done on the client as part of #150

[cooljeanius]

My Actions page just became unreadable due to the original problem described here