Updated a majority of the example scripts to the new api.

Updated the following files to adhere to the new api:
- 2drepresentation.py
- addition.py
- combining.py
- communication.py
- controlledintegrator.py
- controlledintegrator2.py (Note: still using dictionary as output param in make_node)
- controlledoscilatory.py
- integrator.py
- manyneurons.py
- matrix_multiplication.py
- multiplication.py
- oscillator.py
- singleneuron.py
- squaring.py
- twoneurons.py

Added a network array example: network_array_2d.py (might be changed pending renaming of "network array" term)