Game loop, canvas is only redrawn while the game is running
Entities can request not to be rendered (for key listener objects, game state objects, etc).  Space bar will start and stop the game loop via listener entity
Renderable and collidable components

Reorganized file structure a little.  Systems have their own folders now.
Basic text rendering
Behavior system and Follow command
Half of a Line renderable implementation
Moving draggable to behaviors
Fixed draggable behavior
Entity anchoring
Draw line from a source entity to another entity in the scene behavior
DrawLineBetween can be cancelled by clicking anywhere other than another entity
Global listeners distinguish between events
Drag events separated from click events.  Also cleaning up working branch
Removing old working directory
Basic physics
Globally listening entities are only triggered when no other entities receive the event
Working AABB collision test
Limit entity to one collidable.  General collide method wired to tests
Static object collision (e.g. ground)
Controller component