When checking if relative URL is local, take baseUrl into account

Links with empty schemes (href="file.html") or anchored links
(href="#someid") should now be treated as local links if base
url is local.

See <https://bugs.webkit.org/show_bug.cgi?id=94360>.

Change-Id: I31e254ad7341bd54965c91d2e9dd2fbff7a99776
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>