Fix deselection of options on single selects
Update example code to reflect native (framework-less) syntax
Removing a class should not make it uppercase or leave trailing spaces.
Ensure relatedTarget is not null before trying to use it.

With the mouseover event, the relatedTarget property will be null if the mouse cursor originates outside the browser window.
remove_class needs to leave a trailing space in the class name

Ideally the CSS class manipulation utilities should have unit tests around them (see eg. https://github.com/Daniel15/JSFramework/blob/master/tests/dom.js#L25)
Fix some rogue jQuery references that were missed during conversion.
Support for browsers that use currentStyle instead of getComputedStyle
Fixes for legacy Internet Explorer