fix typo in getFontSize
update perf-test.html
add MultiPlay.io to the list of sites
some coffeescript errors can be detected only with compile
Insert charset utf8 for static highlighter demo
   fixes #1385
Adjust fold-widget visibility based on folding-enabled

Slight adjustment to the visibility of `.ace_fold-widget` so that when the `.ace_folding-enabled` flag is toggled, so is the widget's visibility. This addresses the issue where the left-most edge of the folding widgets may still be visible after disabling code. folding
Addresses an issue where IE8 does not properly handle the RegExp in _parseTag, causing folding not to work for the XML mode (or modes that inherit XML). Tested XML mode in IE8/9 and major browsers. Should resolve ajaxorg/ace#1384