Update Teeworlds to 0.7.3.1

Summary:
Summarized changelog for 0.7.3:

• Advanced scoreboard with game statistics
• Joystick support (experimental!)
• Copy paste (one-way)
• Bot cosmetics (a visual difference between players and NPCs)
• Chat commands (type / in chat)
• Players can change skin without leaving the server (again)
• Live automapper and complete rules for 0.7 tilesets
• Audio toggling HUD
• An Easter surprise...

Full changelog here.

Changelog for 0.7.3.1:

• Fixed using correct array measurements when placing egg doodads
• Fixed demo recorder downloaded maps using the sha256 hash
• Show correct game release version in the start menu and console
• Fix platform-specific client libraries for Linux

Test Plan: Played a multiplayer match.

Reviewers: Triage Team, JoshStrobl

Reviewed By: Triage Team, JoshStrobl

Subscribers: JoshStrobl, DataDrake

Differential Revision: https://dev.getsol.us/D6071