Converted win32 to new keyboard state tracking design. Also

changed locking to screen so that keys no longer count (only
mouse buttons and scroll lock toggled on).  This is to deal
with the unreliability of key event reporting which can leave
us locked to a screen with no key physically pressed.  The
result of this is that clients get key repeats and releases
without the corresponding key press.  CKeyState handles this
by discarding repeat/release events on keys it hasn't seen go
down.  Also made a few other minor fixes to win32 keyboard
handling.

lib/platform/CXWindowsKeyState.cpp

@@ -174,6 +174,13 @@ CXWindowsKeyState::mapModifiersFromX(unsigned int state) const
 	return mask;
 }
 
+bool
+CXWindowsKeyState::fakeCtrlAltDel()
+{
+	// pass keys through unchanged
+	return false;
+}
+
 const char*
 CXWindowsKeyState::getKeyName(KeyButton keycode) const
 {
@@ -864,7 +871,7 @@ CXWindowsKeyState::findBestKeyIndex(KeySymIndex keyIndex,
 	// if the action is an auto-repeat then we don't call this
 	// method since we just need to synthesize a key repeat on the
 	// same keycode that we pressed.
-	// XXX -- do this right
+	// FIXME -- do this right
 	for (unsigned int i = 0; i < 4; ++i) {
 		if (keyIndex->second.m_keycode[i] != 0) {
 			return i;