Component upgrades, and improvements to routing

New features in this main release (available now on PyPi):

• Automatic hashing of components and automatic referencing (to prevent duplicate cells).
• Migration of all components to a new Component() class, rather than directly inheriting from gdspy.Cell classes.
• Euler bends now available for waveguide routing! Also, S-bends!
• Better handling of polygon points (number of points are automatically computed to make sure grid errors are below the threshold specified in the WaveguideTemplate)
• Multiple waveguide paths can be specified for routing at once (rather than just one clad path)

First major release!

Library now includes critical building blocks for most common passive photonic integrated circuits:

• Strip, slot, sub-wavelength grating waveguides
• MMIs
• Directional couplers, broadband directional couplers, etc,
• Improvements to the spiral class
• and many more, now in the documentation

Also included now are functions for quickly performing mode calculations or FDTD calculations of sub-components using MEEP/MPB, the PICwriter cell, and a user-specified vertical material stack.

v0.1

First release of the PICwriter library