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/bbb_cape/src/bbb/uart_receiver.h b/bbb_cape/src/bbb/uart_receiver.h
index ab6f019..36bb170 100644
--- a/bbb_cape/src/bbb/uart_receiver.h
+++ b/bbb_cape/src/bbb/uart_receiver.h
@@ -10,14 +10,14 @@
 namespace bbb {
   
   class UartReceiver {
-    speed_t baud_rate_;   
+    uint32_t baud_rate_;   
     size_t packet_size_, stuffed_size_;
     int fd_;
     uint32_t buf_used_;
     char *buf_;
   
   public:
-    UartReceiver(uint32_t baud_rate, size_t packet_size);
+    UartReceiver(uint32_t baud_rate);
     ~UartReceiver();
     // Opens file descriptor, etc.
     int SetUp();