Fix host/port handling in UrlRequest

[KeyWeeUsr]

Closes #2575

Note that this does NOT handle the authentication, just appends user:pass part to the host if applicable, therefore the host + port part is handled correctly, however, when the credentials are specified, it will most likely fail (no test url to check unfortunately) if it's not handled via HTTPConnection or socket (probably not).

[tshirtman]

http://httpbin.org/ can be used to check http protocl, it has enpoints for authentication

[KeyWeeUsr]

Thanks for the link, I could implement basic auth with that. I removed those manual checks for URL parsing as we use the defaults from urllib now (CPython has unittests for that) + added cases for auth through header and via this syntax:

http://user:pass@domain.xyz