Improve Daemon console UI

Summary:
Makes various fixes to the Daemon console UI:

• Removes timeline, timeline cursors, and timeline-related controllers. This abstraction is all but dead and just waiting on an eventual cleanup effort with Facebook (see T2003). There's no need to inspect or debug it anymore.
• Instead of showing the 15 most recently launched non-exited daemons, show all the running daemons. With the old rule, "dead" daemons tended to build up at the bottom of the list -- e.g., secure.phabricator.com shows the 7 active daemons, then 8 dead daemons from as far back as Aug 2012. Showing running daemons is far more useful.
• Simplify the two "Running Daemons" and "All Daemons" subviews into one "All Daemons" subview. The main console now has "running daemons", effectively.
• Create a "Recently completed tasks" view, which shows how many tasks of each task class have completed in the last 15 minutes and how long they took on average. Understanding how quickly tasks are completing is one of the most common uses of the daemon console, and it's currently almost useless for that. Now that we archive tasks, we can show this information in an easily digestable form.
• Partially modernize all of the remaining views.

Test Plan: Looked at daemon console.

Reviewers: btrahan, chad, vrana

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2372, T2003

Differential Revision: https://secure.phabricator.com/D4573