* test: slq2sql more test cases; now executes the generated query
* groupby: first test case working against all DBs
* sakila: added sqlserver 2019 source
* groupby: tests for groupby synonyms
* groupby: final touches
* sakila: initial test data
* sakila: more test data
* sakila: yet more test data setup
* whitespace cols: now working for sqlite
* grammar cleanup
* whitespace cols: now working inside count() func for sqlite
* whitespace cols: tests mostly passing; begining refactoring
* grammar: refactor handle
* grammar: more refactoring
* grammar: rename selElement to selector
* wip
* all tests passing
* all tests passing
* linting
* driver: implement CurrentSchema for all driver.SQLDriver impls
* driver: tests for AlterTableRename and AlterTableRenameColumn
* undo reformat of SQL
* undo reformat of SQL
* undo reformat of SQL
* undo reformat of SQL
* implementation work for json importers
* json driver checkpoint
* working on json.ParseObjectsInArray
* json.ParseObjectsInArray seems to be working
* checkpoint while tidying up ParseObjectsInArray
* more tidy checkpoint
* more tidy checkpoint 2
* tidying up ParseObjectsInArray
* tidy up
* code/docs cleanup
* more cleanup of json driver
* more cleanup of json driver
* flat json import seemingly working
* improvements to json driver
* json writer now prints empty [] for postgres empty tables
