Fix asset pack definition

Signed-off-by: John McCutchan <john@johnmccutchan.com>
GameLoopHtml constructor and asset_pack loading fix.

Signed-off-by: John McCutchan <john@johnmccutchan.com>
Merge branch 'master' of https://github.com/johnmccutchan/tilebasedwordsearch
build copies assets