Tweaks to login dialogs

I made some tweaks to the login sequence. The main login prompt, while still looking the same to the user, now looks more like a form to the browser. This has the advantages that the password manager of the browser works and that the Enter key logs you in. Previously you had to click the login button with the mouse. That was mostly for my own convenience. I also improved the character selection. It's still not beautiful, but definitely less ugly. The user at least realizes what to click on.

I will leave the final CSS styling for shortly before launch when I finalized the overall graphic design of the game. The login sequence is the first impression the user has of the game. It must look as awesome as possible.