improve localhost detection

[James-Mart]

No description provided.

[James-Mart]

Regexes should now cover:

    localhost
    localhost:port
    page.localhost
    page.localhost:port

    127.0.0.1
    127.0.0.1:port
    page.127.0.0.1.sslip.io
    page.127.0.0.1.sslip.io:port

    [::1]
    [::1]:port
    page.--1.sslip.io
    page.--1.sslip.io:port

[swatanabe]

I was going to complain that this matches localhost42, but a quick look at my /etc/hosts shows that that may be a good thing:

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6