it kinda works...
fixed the same bug as in f34be9d001. evolves fine now.
added life force. which works like energy but does not increase over the lifetime of an organism. prevents immortality.
restrict angle of organism to [-PI, PI] so it is the same as the return range of atan2.

added some macros for ease of testing.
cleaned up and reformatted several files. no change in functionality.
world.h - some std::vector changed to std::list to improve speed

stdafx.h - added some pragmas to suppress warnings
changed spawning algorithm. Old: choose two randomly from the top five best performers ever to mate. New: choose two randomly from the current population, with better performers having higher chance of being chosen.

press 2 to show current top scores.
Organisms now control their own speed, and energy loss depends on the speed

New neural network inputs: square of the distance to the nearest plant, own speed
New neural network outputs: acceleration

Moved around some constants.
Normalized inputs to [-1,1].

Simplified the closest plant algorithm.
synchronized with three-layer-brain
small bug fix and adjustment
small bug fix and adjustment

(cherry picked from commit fa066ec4a6d9d50a429a14e0f67634091d20ac20)
added the general signal system and poisonous plants.

restructured a lot of files.
Merge branch 'general-signaling-system' into homogenous-brain