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

Lib/delay.h

@@ -0,0 +1,48 @@
+
+#ifndef __DELAY_H
+#define __DELAY_H
+
+#include <stdint.h>
+
+// Convenience Macros, for delay compatibility with AVR-GCC
+#define _delay_ms(val) delay( val )
+#define _delay_us(val) delayMicroseconds( val )
+
+
+// the systick interrupt is supposed to increment this at 1 kHz rate
+extern volatile uint32_t systick_millis_count;
+
+static inline uint32_t millis(void) __attribute__((always_inline, unused));
+static inline uint32_t millis(void)
+{
+	return systick_millis_count; // single aligned 32 bit is atomic;
+}
+
+
+static inline void delayMicroseconds(uint32_t) __attribute__((always_inline, unused));
+static inline void delayMicroseconds(uint32_t usec)
+{
+#if F_CPU == 96000000
+	uint32_t n = usec << 5;
+#elif F_CPU == 48000000
+	uint32_t n = usec << 4;
+#elif F_CPU == 24000000
+	uint32_t n = usec << 3;
+#endif
+	asm volatile(
+		"L_%=_delayMicroseconds:"		"\n\t"
+		"subs   %0, #1"				"\n\t"
+		"bne    L_%=_delayMicroseconds"		"\n"
+		: "+r" (n) :
+	);
+}
+
+
+void yield(void) __attribute__ ((weak));
+
+uint32_t micros(void);
+
+void delay(uint32_t ms);
+
+#endif
+