Siepic-ebeam-pdk

Cleanup:
- removing old files to make the PDK smaller

KLayout updates:
- wavelength length measurement
- waveguide resize
- Toolbar button for INTERCONNECT

CML updates:
- ebeam_wg_integral loss dB/cm updated based on experimental results

FDTD simulation files
- added files for the grating coupler
- added files for the terminator and disconnected

- Monte Carlo GUI
- Monte Carlo CML component – INTERCONNECT calls FDTD, and updates S-Params
- Waveguide resize
- Monte Carlo for most components (GC, Y, waveguide)

- ring Monte Carlo; using point-coupled model for interpolation; Sparam model for the nominal design simulation.

- Ring resonator CML update

- GUI for the Monte Carlo simulations

- Added Monte Carlo for the directional coupler used for ring resonators
- automated S-parameter generation for both nominal design simulation, and for Monte Carlo