Added basic driver example use code to the library documentation.

Made the USARTStream global public and documented in the SerialStream module, allowing for the serial USART stream to be accessed via its handle rather than via the implicit stdout and stdin streams.

LUFA/Drivers/Misc/TerminalCodes.h

@@ -49,7 +49,7 @@
  *        compiler via the -D switch to disable the terminal codes without modifying the source, for use with non
  *        compatible terminals (any terminal codes then equate to empty strings).
  *
- *  Example Usage:
+ *  <b>Example Usage:</b>
  *  \code
  *      printf("Some String, " ESC_BOLD_ON " Some bold string");
  *  \endcode