* Experiment with individual types for each string
* Fix bunch of errors
* Fix a few more issues
* Fix a whole bunch of bugs
* Fix most remaining bugs
* Fix isset warnings
* Fix psalm errors in psalm
* Limit big string size
* Fix falsiness of ints
* Fix issue with type widening, allowing value set in nested if to be altered
* Don’t complain if type is mixed
* Add skipped-for-now test
* Add specific test to address issue
* Add tests for keyed integer assignemnt
* First pass to get keyed integer assignment working
* Fix array assignment to object-like with different key type
* Improve treatment of objectlikes for callable and iterable comparisons
* Fix array assignment to strings and addition
* Convert expression to CNF
* Do better at merging property types
* Fix array_rand key type
* Rewriting and streamlining every unit test with data providers.
All unit tests have been rewritten into PHPUnit data providers
to reduce the amount of unnecessary code-reuse through out the
test suite.