Optional support for canonical URL meta tag.

[jmhobbs]

This is very roughed in, but it adds support for returning the URL as provided by the canonical link element.

There isn't anything to determine precedence with og:url.

Has passing tests, and is disabled by default.

Needed this for a project, not sure if it would be useful upstream.

[michaelhelmick]

Thanks! One quick thing, can you provide a link on the internet I can test this against? Also, do you think we need to make it a setting?

Also, feel free to add yourself to AUTHORS.

I can see this being useful! :D

[jmhobbs]

Here's a test URL with a canonical tag on it;

https://dl.dropboxusercontent.com/u/28665584/lassie-canonical-urls/index.html

I made it a setting because I didn't want to change existing behavior, I'm fine with it being default though.

[michaelhelmick]

I meant to delete the later question. Haha. I realized the other stuff was a setting.

I'll test this tomorrow morning and get a release out

[michaelhelmick]

0.6.0 is available on pypi!

[jmhobbs]

Thanks @michaelhelmick!🎈🎊🎂