Use split and join instead of substr

[Anthony Dillon]

I would suggest use split and join instead of substr in the toggleClass and removeClass function for speed.

- classString = classString.substr(0, nameIndex) + classString.substr(nameIndex+className.length);
+ classString = classString.split(className).join('');

Do not need the nameIndex variable then as the indexOf is only referenced once. So can move into the if conditional statement.