* Eliminate boundless reads in merge, new compositing implementation (#3234)

* Eliminate boundless reads in merge, new compositing implementation

Resolves #3228

* Fix nits

* Compare non-zero mean of arrays

* Implement and use Window.align()

Combines the effects of Window.round_offsets and
Window.round_lengths, producing the same effect as gdal_merge.py

* Remove unused math import

* Add more docs about align()

Also increase the fraction used in round_offsets() to be
consistent with align()

* Move align() to a private func, use two existing methods in tests

* Add a test for merging WarpedVRTs (#3237)

Resolves #3196

* Backport of #3217 (#3243)

* Backport of #3217

* Update change log

* Increment GDAL and Python versions for CI (#3244)

* Rewrite _matches() to better support to_authority() and to_epsg() (#3255)

* Rewrite _matches() to better support to_authority() and to_epsg()

Resolves #3239

* Remove list() call and update change log

* Use to_epsg() in is_epsg_code() (#3258)

* Use to_epsg() in is_epsg_code()

Resolves #3248

* Update change log

* Allow MRF compression to surface in properties (#3259)

* Allow MRF compression to surface in properties

Resolves #3256

* Update change log

* Register drivers at most once per process (#3260)

* Register drivers at most once per process

Resolves #3250

* Appease flake8

* Add a note about GDAL_SKIP in the change log

* Support all GDALFillNodata() options in rasterio.fill (#3265)

* Support all GDALFillNodata() options

Resolve #3175.

* Cast values to str and update docs

* Update change log

* Prevent rasterio from trying to open a dataset object (#3266)

Resolves #3105.

* Fix typos discovered by codespell (#3264) (#3267)

* Fix typos discovered by codespell

* crasher



---------

Co-authored-by: Christian Clauss <[email protected]>

* Fix erroneous masking of 0-valued data (#3268)

* Fix erroneous masking of 0-valued data

Resolves #3245

* Add an assertion about data values and update change log

* This is 1.4.3

---------

Co-authored-by: Christian Clauss <[email protected]>