Sarpy

Added
- Introduction of rational polynomial fitting tools
- New projection helper using rational polynomial model (for speed)

Changed
- Split original AFRL label structures and AFRL/RDE structures for NGA specific
usage
- Split sarpy.processing.orthorectification module into subpackage

Fixed
Correction of population of SICD ModeType for specific ICEYE collection mode SLC

Fixed
Correction of minor bugs in AFRL label structure population and serialization

Changed
More improvements to Capella SLC reader. *(Remains an incomplete work-in-progress.)*

Fixed
- Completes resolution of bug with unicode handling in sicd validation from 1.2.41
- Correction to SICD and SIDD writing for image segmentation to comply with
standards requirements. *(Before here, "large" images with more than 99,999
columns were incorrectly segmented.)*

Fixed
Resolves bug with unicode handling in sicd validation.
*(This proves to be incomplete.)*

Changed
Updates AFRL label structures with agreed changes