rewrite: wombat update 2.0! Using Object.defineProperty() to better
override .href and .hash properties when possible.
.href returns original url, but on assignment rewrites before redirecting
.hash proxies to location.hash
Also added:
- window.top -> window.WB_wombat_top
- document.referrer -> document.WB_wombat_referrer
- <source> html tag rewriting