todo

TODO

DONE
- Add command line argument parser
- Add multi-threaded neuron updater
- Add functions to change global vars like DEBUG and MUTATE_PROB
- Add unlink_neuron function
- Add link_random_neuron
- Add random brain mutation
- Add neuron types: sensory, motor, intermediate
- Add function to add extra neurons and link them with existing neurons
- Add free neuron function to delete neurons
- CSV parser to generate brain from a CSV file
- Add function for evaluating the brain
- Update save_brain for csv format

CANCELED
- Add sim sharing support so that multiple devices can
  communicate over network to simulate a single brain
- Add load balancer to decide sleep time, how many neurons each thread should process
  based on the b->nc and current cpu usage