puzzle startup. The puzzle web pages now enclose the whole puzzle
(buttons, canvas, permalinks) in a div set to display:none, and
instead display an apologetic message saying 'sorry, it didn't work';
then, if we get through the whole init function without crashing, we
show the puzzle and hide the apology.
[originally from svn r9802]
applets, here's an alternative webification in Javascript, using
Emscripten in asm.js mode (so that as browsers incorporate asm.js
optimisation, the game generation should run really fast).
[originally from svn r9781]
