#49 Made browserify create global numbers object.

Fixed OP issue from https://github.com/sjkaliski/numbers.js/issues/49
- Updated browserify version number to take advantage of the `--standalone` [option](https://github.com/substack/node-browserify#usage).
- Ran build process to update `number.js` and `numbers.min.js`
@LarryBattle the build is failing because of this for older versions (0.8, 0.6). check this: https://travis-ci.org/sjkaliski/numbers.js/jobs/35846621