Old legacy: Rendering

This merge request won't be merged. It used old opengl stuff and can be seen as "first try"

ToDo:

• rendering of blocks
• spectator mode moving around
• Rendering of more complex geometry
• no longer save the allTextures.png
• resizeable Window
• colse Connection on Gamewindow close
• Multi connection handling
• Physics (Gravity, Velocity, Collisions)
• Chat
• Title
• Movement
• Scoreboard
• Tab List
• BossBar
• Inventory (Chests, Hotbar, ...)
• Block placing / breaking
• Entities
• Particles