Added death, consumption, movement

Allowed organisms to add/remove themselves from their parent ecosystems.
Also added a method to get squares adjacent to an ecosystem. Also added
basic eating, allowing an organism to increase its energy (for when it
photosynthesizes or eats something).
Resolved conflicts, added latest master with manifest.
Tested migration/death/feeding (with manifest)
Merged Simon's changes to master. Features should be verified by simon.