Multiband indexing improvements

Relatively small changeset, but some compatibility-breaking changes in multiband raster indexing operations

Fix resample regression in 0.8.2

v0.8.3

fix regression in 0.8.2 related to RegularGrid.resample

minor bugfix release

changes since 0.8.1:

• bugfix for windows (e80401d)
• nodata_value property exposed on RegularGrid
• experimental RegularGrid._align_origin method
• resample_* functions in raster.crfuncs now take an na parameter

v0.8.1: bugfix release

- corrected read bug where GeoJSON feature properties incorrectly tested prior to coercion into karta data model

v0.8.0

• refactor GeoJSON support into external module,
  picogeojson
• removed __setitem__ and __delitem__ methods from MultiVertex, as part of
  a move toward treating singlepart geometries as immutable
• removed xyfile module
• removed several custom Exception types
• remove flat_distances_to(), and allow distances_to to take a crs kwarg
  instead
• remove Point.coordsxy()
• remove RegularGrid.coordmesh() and RegularGrid.center_coords()
• remove warpedgrid
• remove aliases gtiffread and aairead (these have been deprecated for ?
  versions now)
• renames:
  • read_gtiff -> RegularGrid.from_geotiff
  • read_aai -> RegularGrid.from_aai
  • get_coordinate_lists -> aslists
  • get_vertices -> asarray
  • rotate2d -> rotate
• remove deprecated SphericalCRS and EllipsoidalCRS
• indexing a CompressedBand instance with a scalar now returns a row vector
• new function merge_multiparts to combine multipart geometries
• Multipart constructors are now more strict about what they will accept as
  data. Values for the data kwarg are now required to be Table or
  dict-like, the the length of individual dict values is checked

v0.7.4

Bugfix release. Changes include:

• indexing fixed for CompressedBand
• bbox fix for empty Multipart geometries
• fixes for geometry mutations

0.7.3

• aliases for compatibility with code written using karta 0.8
• geographical CRS area fix (5a0e821)
• resize nodata fix (d1e7f98)
• coorectly handle NaN nodata in new read_from_geotiffs function (a831d0f)

0.7.2

• performance: convex hull calculation cythonized and extended for spherical
  coordinates
• performance: planar length calculations are much faster (~700 x) and geodetic
  length calculations are somewhat faster (~1.8 x)
• fix: CompressedBand now always returns array when indexed with a slice
• fix: output dimension of grid sampling methods is now always one larger than
  the input
• raster.merge now works with multiband grids
• efficient algorithm for intersection detection in planar and spherical
  coordinates
• new read_gtiffs function for reading multiple files as bands
• implement experimental RegularGrid.coordinates() method returning a
  CoordGenerator object
• implement get_coordinate_lists for Multiline and Multipolygon
• other performance optimizations and fixes

0.7.1

bugfix release:

- fix issue with mask_by_poly that could sometimes give garbage results
- better support for multiband array via BandIndexer

0.7.0

release version 0.7

Changes:

- major refactor of geometry hierarchy
    - adds Multiline and Multipolygon classes
    - polygon vertices are double-nested in order to represent sub-polygons
    - only multipart geometries now contain a data attribute
- GeoJSON now attempts to project all data to geographical WGS84 coordinates as
  per https://datatracker.ietf.org/doc/draft-ietf-geojson/
    - `force_wgs84=False` can be set to avoid this behaviour
- multivertex geometries now use CoordString as a data backend, which should
  permit faster operations on the C side
- rename `Line.subsection` -> `Line.to_npoints`
- new R-tree implementation in C
- `projected` keyword argument added to `Point.distance`, `Point.azimuth`, and
  `Point.walk` to control whether geodetic or planar algorithms are used with
  the CRS is not geographical
- replaced polygon membership testing algorithm with a winding number-based test
- implemented fallback algorithm for polygon membership testing in polar regions