Better variable name.
Sacrifice some minification for performance with property names.
Documentation fixes.
Widened input range for selecting by id or class.
Removed WebKit single selector.
Turns out document.querySelector() is also a history-caching function.
http://jsperf.com/fbsinglesel/7
Faster selection by class with only one token.
http://jsperf.com/parseclass
Added explicit $QS and $QSA functions.
Cleaned up the .show() function.
The added stuff can easily be accomplished by a user with the .css() function.