Refer to `global` instead of `window`

Change .jshintrc to have "node":true instead of "browser":true. This makes it
more difficult to accidentally globally reference non-ECMAScript globals, as
was done with `URL` in 40963655c6d75b6b44fd396153db3b458ec04da4

Note: browserify ensures that bundles use `window` for `global`:

  https://github.com/substack/browserify-handbook/tree/12f07d9767192d3f26510fbf2d79f3cdf13e18b6#global

see #94