Dtools-datastructures

* designing sensible reduce & accumulate overrides for Maybe & Either
* default implementations were not that useful
* taking their behavior as bugs and not API changes
* more tests for accumulate & reduce
* fixed Stack reverse() method
* should have caught this when I fixed FStack on last PyPI release
* more Stack tests
* many more FP tests

* BUG FIX: FStack reverse() method
* added more tests

* Considerable future-proofing for first real Beta release

* Package structure mature and not subject to change beyond additions
* Will endeavor to keep top level & core module names the same
* API changes will be deprecated before removed

* A lot of work done on class CLArray
* probably will change its name before the next PyPI Release
* perhaps to "ProcessArray" or "PArray"
* Keeping this release an Alpha version
* mostly for the freedom to rename and restructure the package

* Second release candidate - probably will become next PyPI release
* main now development branch, release will be release branch
* decided to drop it back to Alpha
* making datastructures a Beta release was premature
* classifier "Development Status :: 3 - Alpha"
* will cut next PyPI release with Flit from release branch
* will need to regenerate docs on release & move to main
* things to add in main before next release
* will not make Maybe Nothing a singleton
* last touched CLArray refactor
* improve CLArray test coverage
* Things for future PYPI releases
* inherit FTuple from Tuple (use __new__) for performance boost
* hold off using __slots__ until I understand them better