[CRUSH-build] remapping the joysticks

[Bill Bennett]

Joe worked up a spreadsheet program that allowed us to play with curve 
shapes of the joystick to output response. We refined this a bit during the 
meeting today, then embodied it in a table lookup routine which is now used 
in the tank mode code. We tested it on FWIPER and Joe and I think it's 
pretty nice. It's a three segment function, mirrored on each side of zero. 
Segment 1 is a deadzone, segment 2 uses a low slope, and segment 3 a steeper 
slope. Additionally, there is a step function at the dead zone that starts 
the motor with a usable current immediately after the deadzone, rather than 
using part of the joystick range to move from zero to lowest usable current. 
The effect is that there is no "hum zone" where the motors are humming while 
trying to turn without enough power to actually move the robot.

I migrated this code to the eclipse version so it's ready to try in Kareem. 
I didn't commit it to CVS yet.

Bill