Add F keys and print screen
#define CLCK 0x39
#define F1 0x3A
#define F2 0x3B
+#define F3 0x3C
+#define F4 0x3D
+#define F5 0x3E
+#define F6 0x3F
+#define F7 0x40
+#define F8 0x41
+#define F9 0x42
+#define F10 0x43
+#define F11 0x44
+#define F12 0x45
+#define PRSC 0x46
#define HOME 0x4A
#define PGUP 0x4B
