Updating firmware on mp3 player

Developers must use this rev, as it is hard to add anything with the DSEG problem in 0.6.2. There is a status line on the top that shows if the player is playing or paused, and if it's in normal or random mode.I also re-arranged much of the display code to more-or-less do much of the display abstraction stuff that was discussed in the yahoo group a couple weeks ago.He's got some of the navigation with the arrow keys.

This rev also includes Ian's latest work on the user interface.Tom put in file_uncache, and Ian added the redisplay to deal with the beta test display problem that shifts everything a couple pixels.Zach sent some code that scans subdirectories (only prints their contents for testing and isn't called yet) and I fixed a few bugs. A bug in the Makefile was fixed which would not completely rebuild the code with an updated DRAM controller.The simm test command 'T' does more useful tests and usually prints more useful information.