Creates new class for representing cell state closes #36

	new file:   cellular_automata/states/__init__.py
	new file:   cellular_automata/states/base.py
Implements new state class

	modified:   cellular_automata/cells/base.py
	modified:   cellular_automata/cells/regular.py
	modified:   cellular_automata/lattices/equiangular.py
	modified:   cellular_automata/rules/base.py
	modified:   cellular_automata/rules/game_of_life_rule.py
	modified:   cellular_automata/rules/neural_rule.py
	modified:   cellular_automata/rules/number_rule.py
	modified:   cellular_automata/rules/stochastic.py
	modified:   cellular_automata/states/base.py
Adds usage of new cell state class. Many improvements