Use value rather than nodeValue in attributes (it's the string version). Update sizzle: default attribute handling.

Remove reverse in traversing for comma selectors. Sizzle's handling of commas is now more consistent.

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>

We don't want a disabled link/button to register delegated clicks, but we do want events like mouseover or custom events.

This is a compromise, there is no perfect solution. Well, the browsers could be consistent about direct vs. delegated events but *that's* not gonna happen.

This fixes a regresssion from 1.6.4. Be aware that nearly every place that this bug comes into play, the selector in use is incredibly inefficient.