Allow passwords longer than 11 characters

It is poor security practice to set a maximum length on a password, especially one as low at 11 characters. I kept the minimum at 4 characters just to not break backwards compatibility, but it should really be a minimum of 8 characters these days.
Merge pull request #218 from mfjordvald/patch-1

Allow passwords longer than 11 characters. I agree @mfjordvald