Updates for playback in CVS

[Jeffrey Nowakowski <jeffno@ccs.neu.edu>]

I've made several improvements to COW playback with CamBot in mind.
They are:

- Can jump to any point in recording.
- Can lock on to cloaked players.
- Tactical/galactic repaint when paused.
- Can lock on to different players when recording paused.

The interface to jump around the recording is a bit cryptic, but until
someone creates a GUI with VCR buttons, it'll have to do.

Here's how it works:

You can hit '=' to find out where you are in the recording.  It'll
then spit out on stdout something like "sequence #15702" if you were
about halfway through the game (there are roughly 30000 sequences, or
updates, in a typical cambot recording).

To jump to sequence number 12345, you would type the following input
characters: j12345j

The first 'j' says to start accepting jump input, and the second one
marks the end of input.  If you make a mistake while entering numbers,
you can hit 'J' to abort.

Like I said, it's cryptic, but it works.

-Jeff