Release v2.0.0

- New build system based on autoconf
- Major bug fix for relative azimuth angle and scattering angle
- New Sensors
    - JPSS-2 / NOAA-21
    - VGAC Fusion
    - AMI
- Added tracing hooks used for super-resolution and parallel segment
  processing
- Major overhaul of ECM2 that fixes numerical stability and multiple
  other bugs
- Bilinear sample the prior cloud probability
- new NetCDF format for DCOMP tables