Adding initial Teensy 3 support, compiles, but not fully functional yet.

- CDC Output seems to be working
- USB Keyboard output has not been tested, but is "ready"
- UART and Timers have not been tested, or fully utilized
- Issues using Timer 0
- Initial template for MBC-55X Scan module (only module currently compatible with the arm build)
- Updated the interface to the AVR usb module for symmetry with the ARM usb module
- Much gutting was done to the Teensy 3 usb keyboard module, though not in an ideal state yet

main.c

@@ -111,7 +111,17 @@ inline void usbTimerSetup(void)
 
 // ARM
 #elif defined(_mk20dx128_)
-	// TODO
+	// 48 MHz clock by default
+
+	// Enable Timers
+	/* TODO Fixme!!
+	PIT_MCR = 0x00;
+
+	// Setup ISR Timer for flagging a kepress send to USB
+	// 1 ms / (1 / 48 MHz) - 1 = 47999 cycles -> 0xBB7F
+	PIT_LDVAL0 = 0x0000BB7F;
+	PIT_TCTRL0 = 0x3; // Enable Timer 0 interrupts, and Enable Timer 0
+	*/
 #endif
 }
 
@@ -125,6 +135,7 @@ int main(void)
 	// Setup USB Module
 	usb_setup();
 
+	print("TEST");
 	// Setup ISR Timer for flagging a kepress send to USB
 	usbTimerSetup();
 
@@ -143,6 +154,10 @@ int main(void)
 			while ( scan_loop() );
 			sei();
 
+			// XXX DEBUG
+			dPrint("AAAAAAA\r\n");
+			print("AAAAAAB\r\n");
+
 			// Run Macros over Key Indices and convert to USB Keys
 			process_macros();
 
@@ -174,10 +189,12 @@ int main(void)
 
 // ----- Interrupts -----
 
-// AVR - USB Keyboard Data Send Counter Interrupt
-#if defined(_at90usb162_) || defined(_atmega32u4_) || defined(_at90usb646_) || defined(_at90usb1286_)
-
+// USB Keyboard Data Send Counter Interrupt
+#if defined(_at90usb162_) || defined(_atmega32u4_) || defined(_at90usb646_) || defined(_at90usb1286_) // AVR
 ISR( TIMER0_OVF_vect )
+#elif defined(_mk20dx128_) // ARM
+void pit0_isr(void)
+#endif
 {
 	sendKeypressCounter++;
 	if ( sendKeypressCounter > USB_TRANSFER_DIVIDER ) {
@@ -186,8 +203,3 @@ ISR( TIMER0_OVF_vect )
 	}
 }
 
-// ARM - USB Keyboard Data Send Counter Interrupt
-#elif defined(_mk20dx128_)
-	// TODO
-#endif
-