Reimplement the StrictMode URL parsing

Reimplement the StrictMode URL parsing

The strict mode check is now implemented after the tolerant parser has
finished, and only if the tolerant parser has not found any errors. We
catch the use of disallowed characters (control characters plus a few
not permitted anywhere) and broken percent encodings.

We do not catch the use of Unicode characters, as they are permitted
in IRIs.

In the tests, remove the old errorString test since it makes little
sense.

Change-Id: I8261a2ccad031ad68fc6377a206e59c9db89fb38
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>