Asteroid

Draw with alpha
Net

Initial commit of classes for network play!
Asteroid, net, Spacescape

Remove enemy creation from Spacescape. This kind of thing is now to be
done by the Director.

Each game has exactly one Director (the host of the game will have that
instance). This Director will control unmanned modules and the creation
of enemies.
Players will tell the Director if they spend energy, give energy,
destroy enemies, etc.

Each player has a Controller. The Controller receives instructions from
the Director, and then executes them on the Game.
Asteroid

Fix little bug causing other images to get drawn with transparency.