Login, character select and character creation screens

The client starts straight into the world from command-line flags, and a character's class and look come from a hash of its name.

• Front end: main menu, sign-in (with accounts-auth), server status, character list, settings (#67) and credits, a loading screen while the world streams in, clear messages for version mismatch and lost connection.
• Creation: name, body (gender, skin, hair and beard from the character packs), starting stats and up to three starting skills inside the ruleset's creation limits (#52), a preview of the character turning, starting kit by skills.
• The server validates the choice and lands the colonist in Aquais.

Done when a tester goes from launching the client to standing in Aquais with a character they made, without a terminal.