field: port panels to opengles-compatible calls
WIP: turret: port to opengles-compatible calls
WIP: baseshape: port to opengles-compatible calls
WIP: shape: remove old display list-based code
WIP: gamemanager: remove final matrix stack calls
color: pass down the color where necessary
screen3d: remove unused methods
screen: remove eyepos method
displaylist: remove utility class
shaders: close programs before GL is shutdown

Static destructors are run after GL is shutdown, so add a close() method
to the Actor class and have the pool close them all.
screen3d: remove matrix manipulation calls
screen3d: remove method used once
screen3d: load GL3 directly

No deprecated features are used anymore.