USB Core porting WIP

Author: cmaglie

hardware/sam/cores/sam/USBAPI.h

@@ -35,7 +35,7 @@ class Serial_ : public Stream
 	virtual int peek(void);
 	virtual int read(void);
 	virtual void flush(void);
-	virtual size_t write(uint8_t);
+	virtual void write(uint8_t);
 };
 extern Serial_ Serial;
 
@@ -101,7 +101,7 @@ class Keyboard_ : public Print
 	void setKeyMap(KeyMap* keyMap);	
 public:
 	Keyboard_();
-	virtual size_t write(uint8_t);
+	virtual void write(uint8_t);
 };
 extern Keyboard_ Keyboard;
 
@@ -163,4 +163,4 @@ void USB_Flush(uint8_t ep);
 
 #endif
 
-#endif /* if defined(USBCON) */
+#endif /* if defined(USBCON) */