Admin: Enhanced dashboard customization

[HeyJoel]

Further to the basic dashboard customization done to satisfy issue #61, it would be good to be able to provide a more substantial dashboard framework that allows easier or more advanced customization of the dashboard using preset modules or the ability to define custom content from your application.

[j7rowan]

Currently is there any other way of overriding the default admin icons file besides building core with a new image file?

[HeyJoel]

If you just want to override a specific file you should be able to do that by placing the new file in exactly the same directory in yoyr website project. Local resources override embedded resources.