Add an abs: pseudo-class selector

[jhy]

We should have an abs: pseudo-class selector, so you can select on the absolute URL of an element. I.e. a[abs:href=...], img[abs:src$=...] etc. Now it could only be on the specific href attribute value.

Also could think about doing URL parsing and then able to select on host, path, query, spec, et all.

Like a[host:href=example.com]. You can kind of do that now with the range query, but that's kind of susceptible to input variations.