Merge pull request #63 from debugger22/develop

Isolated base classes of IC in a different module
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
Removed a small bug in calling _updateHIstory() and commented out unnecessary statements.
Also introduced a few break statements to prevent redundant iterations.
Merge pull request #71 from SharanyaH/develop

Removed a small bug and improved efficiency a tad
Name Conflict in class attribute and class variable and method - inputs
Changed the name of the function to getInputStates()
Changed its functionality to return the states of the input connectors rather than the connectors themselves
Added Examples to explain usage of Pin class, drawIC() method, and IC base classes
Merge pull request #75 from SharanyaH/develop

Name Conflict in class attribute and class variable and method - inputs
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