v2.11.6
Fixed some file permissions (Cygwin loves adding execute)
Moved PR #232 tests into Mocha.
Fixed #133: Thunderbird: raw HTML not rendering properly
Added class name to math image element. Refactored options defaults.
Added tests for some newly exported Utils functions: walkDOM, utf8StringToBase64, base64ToUTF8String, rangeIntersectsNode. Also found bad behaviour in Chrome's Range.intersectsNode, so now we're only using the fail-back code.