PUBLIC MARKS from julie with tags accessibility & extension

Extension accessibilité pour ceux qui utilisent Dreamweaver.

One of the updates from the draft Web Content Accessibility Guidelines 2.0 is a change to the algorithm to determine whether the contrast between foreground and background colours is sufficient . As well as updating the algorithm itself, the thresholds have changed to consider large and bold text (at least 18 point or 14 point bold). I've updated the Colour Contrast Firefox Extension to incorporate the changes.