Finish most of the uart stuff.

I've decided to push this, even though I can't test it.
That worries me a little. Use it with caution.

Implement GPIO stuff, and a main executable to receive uart
data. Also make some modifications to Brian's stuff, to get it to
build correctly.

Finally, add some testing stuff. Feel free to disregard that.
I probably won't be using it until I get debian flashed onto
my BeagleBone Black.
diff --git a/frc971/atom_code/atom_code.gyp b/frc971/atom_code/atom_code.gyp
index a004c4d..4803265 100644
--- a/frc971/atom_code/atom_code.gyp
+++ b/frc971/atom_code/atom_code.gyp
@@ -25,7 +25,7 @@
         #'camera/camera.gyp:frc971',
         '../../gyro_board/src/libusb-driver/libusb-driver.gyp:get',
         '../input/input.gyp:gyro_sensor_receiver',
-        '<(DEPTH)/bbb_cape/src/bbb/bbb.gyp:uart_receiver',
+        '<(DEPTH)/bbb_cape/src/bbb/bbb.gyp:*',
       ],
       'copies': [
         {