… the unexpected results.
Added a feature detect if the browser sets 'null' instead of null in the
Added a `Element.Property` for class.
TESTED: Opera 11, Safari 5, Firefox 3-5, 8, 10, Chrome latest, IE6-9.
Removed unnecessary Element.Properties.class and opted to use
propertySetter and getter. Adding for condition to set the value to ''
instead of null (IE would set to 'null').
Refactored setProperty. Now much simpler. Checks for propertySetter and
assumes it'll take responsibility in cleaning up the value (and to set
it). Still removeAttribute if no setter, and value is null. Passes all
specs, and therefore, it's backwards compatible.
PASSED: IE6-9, FFx 3-5, 8, 10, Chrome latest, Safari 5, Opera 11.