Make sure smartphones can log in

Tested in desktop browsers: Chrome, Firefox, Opera (Classic), IE10
(VirtualBox).
Tested in mobile browsers: Chrome, Firefox, Opera Classic, Opera (the
new one for Android), stock Android browser 2.1 and 4.0 and Safari on an
iPad (iOS 5.1.1). Safari is detected as a mobile browser, though, but
that doesn't really hurt.

Initial fix for issue #7.
Merge pull request #56 from aykevl93/smartphone-compatibility

Zorg dat smartphones in kunnen loggen