Added methods so the viewer can get the list of trees and their size
Change test to use sawmill for test of retrieving production since the woodcutter needs a worker that cuts a tree and this makes the test trickier to write
Added woodcutter worker that goes out and cuts trees. Added tests and updatd existing tests to expect a woodcutter house to need a worker and only produce trees when it's occupied and there are trees adjacent to its flag point
Added a test to make sure the forester stays inside if it has no possible points to plant trees on. Updated the model to handle this case.
Made start and end members in Road private and changed all users to use get(Start|End()() or get(Start|End)Flag() instead