I don't think this quite works for combining the `re_abs_url` and `re_abs_no_proto` regular expressions into one. `re_abs_no_proto` should match this string: `<img src="//asdf.com/mypic.gif">` capturing the `//` part. What you have would match the string `<img src="http:\/\/asdf.com/mypic.gif">` but not the one with the `//` url.

(This is partially my fault.. I majorly need to get some unit tests in place, probably even more than I need performance tests..)