Modified base Classes to include and use pin class which uses operator overloaded logic class for its output state. Added drawIC() method to visually represent the logic state of the pins of an IC.
Added series_4000
Added overloading method for inversion operator in logic class
corrected a few typos
typos
Added Examples to explain usage of Pin class, drawIC() method, and IC base classes
Added drawIC.py - Shows usage of IC 7400 to IC 7420
a few typos
Padding ic_name string with more spaces to accomodate for Bigger IC
Corrected a typo
Added examples for all ICs and moved usage docs for ic classes to docs folder
Merge pull request #68 from rvraghav93/drawIC_and_pin_class

Modified base.py to include and use pin class and drawIC() method