Adjustments to keycode support

dgl/src/pugl/pugl_osx.m

@@ -127,7 +127,7 @@ getModifiers(PuglView* view, NSEvent* ev)
 static unsigned 
 scancodeToHID(unsigned scancode)
 {
-	const unsigned char KEYCODE_MACOS_TO_HID[128] = {
+	static const unsigned char KEYCODE_MACOS_TO_HID[128] = {
     	4,22,7,9,11,10,29,27,6,25,0,5,20,26,8,21,28,23,30,31,32,33,35,34,46,38,36,
     	45,37,39,48,18,24,47,12,19,158,15,13,52,14,51,49,54,56,17,16,55,43,44,53,42,
     	0,41,231,227,225,57,226,224,229,230,228,0,108,220,0,85,0,87,0,216,0,0,127,

dgl/src/pugl/pugl_win.cpp

@@ -383,7 +383,7 @@ setModifiers(PuglView* view)
 static unsigned 
 keycodeToHID(unsigned keycode)
 {
-	const unsigned char KEYCODE_WINDOWS_TO_HID[256] = {
+	static const unsigned char KEYCODE_WINDOWS_TO_HID[256] = {
     0,41,30,31,32,33,34,35,36,37,38,39,45,46,42,43,20,26,8,21,23,28,24,12,18,19,
     47,48,158,224,4,22,7,9,10,11,13,14,15,51,52,53,225,49,29,27,6,25,5,17,16,54,
     55,56,229,0,226,0,57,58,59,60,61,62,63,64,65,66,67,72,71,0,0,0,0,0,0,0,0,0,

dgl/src/pugl/pugl_x11.c

@@ -492,7 +492,7 @@ setModifiers(PuglView* view, unsigned xstate, unsigned xtime)
 static unsigned 
 scancodeToHID(unsigned scancode) 
 {
-	const unsigned char KEYCODE_LINUX_TO_HID[256] = {
+	static const unsigned char KEYCODE_LINUX_TO_HID[256] = {
     	0,41,30,31,32,33,34,35,36,37,38,39,45,46,42,43,20,26,8,21,23,28,24,12,18,19,
     	47,48,158,224,4,22,7,9,10,11,13,14,15,51,52,53,225,49,29,27,6,25,5,17,16,54,
     	55,56,229,85,226,44,57,58,59,60,61,62,63,64,65,66,67,83,71,95,96,97,86,92,
@@ -505,8 +505,11 @@ scancodeToHID(unsigned scancode)
 	};
 
 	//On Linux, the keycodes are offset by KEYCODE_EVDEV_OFFSET when they are sent by evdev
-	const unsigned KEYCODE_EVDEV_OFFSET = 8;
+	static const unsigned KEYCODE_EVDEV_OFFSET = 8;
 
+    if (scancode < KEYCODE_EVDEV_OFFSET)
+        return 0;
+    
 	scancode -= KEYCODE_EVDEV_OFFSET;
 
     if (scancode >= 256)