Youtube

This patch provides an update to the rules used to rewrite YouTube URLs. Specifically it:
- allows rewriting for all YouTube subdomains (previously only www was rewritten)
- allows rewriting for all ytimg subdomains (previously disallowed subsubdomains)
- allows rewriting for all googlevideo subdomains (previously disallowed subsubdomains)
- adds support for regional YouTube domains
- removes redirect from youtube-nocookie.com to www.youtube-nocookie.com
- removes all URL exclusions as YouTube can now work without them

Tested on Chrome (stable) and Firefox (stable) on Linux. Everything is working except Flash object embeds on Chrome, but that's an existing [issue](https://github.com/EFForg/https-everywhere/issues/551).