[ANNOUNCEMENT] Shadow Framebuffer Test 13

[Harold Hunt]

I just posted Test 13 to my usual announcement page:
http://www.msu.edu/~huntharo/xwin/shadow/

Changes
1) The bitmask for detecting right and left
        modifier keys was incorrect.
2) Right and left modifier key detection was
        reversed, had the mask been correct.

Test 13 should finally distinquish betweeen Alt_L and Alt_R, etc.

Harold