Added a list of all agents and their values to the HUD and changed the already existing energy hud element to reflect it no longer is the only text/hud element.
Note that the names of the agents on the HUD is just their id's and that energy is displayed twice (original and new).
Replaced empty lines with comments or nothing and added test vacuoles and emitter
Replaced all tab-stops with four spaces.
Merge pull request #45 from jjonj/hud-agent-addition

Added a list of all agents and their values to the HUD and changed the a...
Add AgentRegistry for managing agent ids

See issue #42, #48