Fix for typo from a recent pull

There is a minor typo in the recent pull  Simple fix.
Merge pull request #416 from detain/master

Fix for typo from a recent pull
Fixed Erroneous HEXTILE test

The HEXTILE test which tested for a background tile followed
by an empty tile was only wide enough to actually test for one
tile, thus not actually testing the functionality.  It now actually
uses two tiles, thus actually testing the functionality.
Add ISO Level 3 Shift (AltGr) to keysym.js
Fixes #309, make use of keysym.js

Bonus 3 bug fixes:
 * Meta is 0xFFE7 not 0xFE07
 * Super_L is 0xFFEB not 0xFFEC
 * Super_R is 0xFFEC not 0xFFED