.jshintrc: set browser:false

Setting `browser:true` predefines a large list of globals. Some of these, like `window`, `location`, and `setTimeout`, are really useful. Some of them, like `name`, `event`, and `status` are really dangerous to have available as globals. They invite code errors.

This PR
 * sets `browser: false`
 * predefines `window`, `location`, `setTimeout` and the other "normal" globals