Water at last

It took long enough but I managed to fix the line of sight code and get the obstacles working properly. Behaviour is a lot better and creature survival times increased, also fixed the bug that caused creatures to occasionally leave the world.

Added water and thirst, creatures now have two needs instead of one, works using linear logic, but is not realistic. Water locations are stationary, can cause problems depending on obstacle configuration, some set-ups much more survivable than others.

Next step improving the decision making algorithm to handle two needs.

Obstacles

Added obstacles to the world, this has had several effects. The creatures movement seems much more natural because the objects cause more changes of direction, the objects make it more difficult for creatures to survive by obscuring food from view.

There are problems caused by creatures becoming "stuck" inside an obstacle, rectifying this problem is the next step. This addition has taken much longer than originally planned and is beginning to set back other areas of the project, I am hopeful I will be able to fix this sooner rather than later.