Updated for current version of dart SDK

offset and page now return Points.
query -> querySelector
update gitignore to properly ignore packages directories.
Remove old JS files, should use pub build now

Also are you interested in maintaining this project? I have some thoughts on converting this to a Polymer Element so it can be placed the same as any input tag in html. Alternative would also be to automatically convert input type=color to use the color picker etc. If not, do you have any objections to my creating a fork based on your work already completed?