Add key combo support

Limelight/Input/KeyboardSupport.m

@@ -248,6 +248,9 @@
             case UIKeyboardHIDUsageKeyboardRightAlt:
                 keyCode = 0xA5;
                 break;
+            case UIKeyboardHIDUsageKeyboardErrorUndefined:
+                NSLog(@"Undefined key pressed");
+                return false;
             case 669: // This value corresponds to the "Globe" or "Language" key on most Apple branded iPad keyboards.
                 keyCode = 0x1B; // This value corresponds to "Escape", which is missing from most Apple branded iPad keyboards.
                 break;