type dropdown, we still get an 'onchange' event if they select it a
second time. Normally this wouldn't happen, because onchange means
what it says and we only get it if a _different_ element is selected.
My solution is to create two list items called Custom, set one of them
as display:none to stop it showing up when the list is dropped down,
and to select it after the configuration box closes.
[originally from svn r9788]
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]
