Let js do the selecting instead of using a settings page

How about removing the settings page and let javascript take care of the selection of DOM elements which should be handled by the png fix. Here's my idea:

The current jQuery pngFix plugin doesn't provide a way to change the sizingmethod, while this sometimes is useful when using background images which should be repeated. This is IMO a big disadvantage of the plugin. Writing a little script which does this is quite simple. When we do decide to switch to our own js, then we could also define our own classes which can be used by other modules (or themes). For example a module creates a div with the class names 'pngfix' and 'scale'. These two class names tell the script that the div has to be handled by the pngfix script (.pngfix), and that the sizing method scale (.scale) has to be used. No need to add the selectors in the admin page anymore and much more possibilities for modules which are depending on the pngfix module.

We can let the script check if the element is an image or has a background image in order to decide what has to be replaced.

I already created something like this a while ago, so I could roll out a patch for this if someone's interested.