Fixed incorrect checkbox behaviour.

Paper checkboxes use the 'change' event to show when they've been
changed, 'click' happens too early.
Removed JS game caching.

It doesn't have any advantage, since data gets refreshed anyway.
Attempted to improve search behaviour.

Paper inputs don't fire `search` events, so listen for enter keyup
instead. However, there's something wrong with search in that I can't
get it to cycle through the matches any more. I tried to add the
findNext variable usage, but it doesn't seem to have had any effect.