Grunt. lint CSS. uglify js. license. update readme

Grunt build task now available to lint and minify css and js files
systematically.

I added a License.md file, you can change it to whatever license you
want.

JS minifies with a copyright banner now. To update the info in that
banner, edit the package.json file.

fixed some typos and whitespace in JS comments.

Fixed the invalid user-select CSS rules.
Re-formatted the non-min CSS to a more readable format.
The .current styles were overqualified, I de-overqualified them.