fix #674 404 link in Doc
fix #676 bump dependencies

Build was failing due to jshint / contrib-jshint incompatibility.
fix #678 Work-around for scrollbars not removed correctly on webkit.

Adds an aria.utils.Dom.refreshScrollbars method as a work-around
for Chrome bug http://crbug.com/240772 (this bug also appears on
some other webkit browsers) : scrollbars are not removed when they
are no longer necessary if the content has nearly the same size as
the container.