get rid of clunky 4-way wire connector
simulation from gui first commit
first semi-working version :) clean up to commence
fix editable text character delete bug
lift up connectors so that it's easy to draw more lines
can now independently plot USR and PZD
cleaned up main.py
cleaned up constants.py
better pole zero diagram, bug fix on plotting poles/zeros with imaginary components
cleaned up gui/board.py
cleaned up gui/components.py
repace straight wire with gain of 1
cleaned up gui/palette.py