Hedgewars: Clean up password fields
completed by: Ondrej
mentors: Andrey Korotaev, Xeli, Sheepy, koda
Recently we spotted a few bugs in QTfrontend/ui/dialog/input_password.cpp: if you input a wrong password you are rejected and have to restart and you have to restart, if you login without nickname you'll lose forever the possibility of inserting a password (unless you go and change it settings) and the field is initially empty.
Can you fix all errors and improve the code?
A working patch, that applies cleanly to our source tree. This patch should be in the form of a pull from clone,
hg export or unified diff format (in order of preference) implementing the functionality required.