Fix handling of some conditional comment tags in HTML message (#1489004)
Added two tests for HTML comments handling in rcube_washtml class
Bump up also RCUBE_VERSION
Fix javascript error in IE9 when loading form with placeholders into an iframe (#1489008)
Better fix for IE9 issue with document.activeElement error (#1489008)
Call resize handler in intervals to prevent lags and double onresize calls in Chrome (#1489005)