Preparing for Teensy 3 (ARM) integration, abstracting code hierarchy

- Abstracted USB Module
- Abstracted compiler specific includes for Scan, Macro, Debug, and USB modules
- Updated CMake build files to support changes
- Added abstractions necessary to main.c as well as a compiler specific include file

Scan/FACOM6684/scan_loop.c

@@ -21,10 +21,8 @@
 
 // ----- Includes -----
 
-// AVR Includes
-#include <avr/interrupt.h>
-#include <avr/io.h>
-#include <util/delay.h>
+// Compiler Includes
+#include <Lib/ScanLib.h>
 
 // Project Includes
 #include <led.h>