On branch master - remove python dependency

cheats/exec_cheat.gmd - does not harness
python rendering anymore to dynamically
generate the ampersand demo images. A
final rendering of these images are now
in the static directory. The scripts and
python file are still available through
download links in the tutorial, for the
terminally curious.

modified:   exec_cheat.gmd
new file:   images/amp.png
new file:   images/coarseamper.png