Siepic-ebeam-pdk

- Photonic wirebond pcell update
- contra DC PCell update
- other minor fixes

- Waveguide PCell uses waveguide generator code from layout_waveguide2 in SiEPIC.utils.layout in SiEPIC-Tools v0.3.64
- Added "width" as parameter in WAVEGUIDES.XML file
- ebeam_rib_phase_shifter and ebeam_rib_phase_shifter_folded update

New components
- ebeam_rib_phase_shifter, using doped heater
- straight IRPH waveguide, doped heater/detector
- ebeam_taper_strip_rib
- alignment marker

Updated:
- IRPH ring resonator with slab
- SWG_to_strip: added SWG block ∆w

New components:
- Bragg grating PCell, with parameters from a file
- broadband 50/50 splitter for 1310 and 1550 operation: ebeam_splitter_swg_assist_te1310.gds
- SWG_assisted_Strip_WG PCell
- Multibox Bragg Grating
- 1310 nm grating coupler, ebeam_gc_te1310_8deg.gds

New functionality:
- Waveguide: support for multiple waveguide CML and models

Fixes:
- waveguide pin width rounding error, which sometimes caused false Functional Verification errors
- other minor fixes

- contradirectional coupler
- several fixes
- added parameter for simulation accuracy
- Photonic Wirebonding cell
- updates to CML
- PCM spiral data

- fixes to CDC