Loosen up query check

[gjtorikian]

This loosens up the external URL checks for URLs with queries. For example:

<a href="https://github.com/contact?form%5Bsubject%5D=New+Assigned+Events">First</a>

<a href="https://github.com/contact?form%5Bsubject%5D=Organization+and+Team+Membership+APIs">Ignored</a>

<a href="https://github.com/contact#false?form%5Bsubject%5D=Organization+and+Team+Membership+APIs">Second, because of hash</a>

<a href="https://github.com/contact?form%5Bsubject%5D=Blah+and+blah+blah+APIs">Ignored</a>

It doesn't matter that contact?form has multiple values. The URL is essentially the same.

In this PR, we'll consider a URL with queries different if and only if it has different query parameters, not different query values.