Add section on 'Extending Native Prototypes'
Update jshintrc:

- Add Frog as pre-defined global
- 4 spaces instead 2 for indentation
- Remove 'use strict' enforcement
- Enforce use of curlys for blocks
- Add `es3` option for enforcing IE8 compatibility
- Prohibit native object extension (i.e. Object, Array, Date, etc)