Very simple beginnings of a game GUI library.
More presentable buttons.
Add better DSL.
Build actual game GUI.
Add label to GameUI
Change the way action use works.

We now "target" entities to interact with. Better for touch interface...
and also to avoid some stupid stuff that happens in SS13 (frantically
clicking, trying to overcome lag in the face of angry wizards).
Cleanup; can select via right click for now as well.
Fix indentation for protocol docs.
Make set_gamestate's payload a proper JSON object.
Move some network handling logic out into citadel_network
Relocate "looking at" debug string.