Initial pull

- There appears to be an expectation of a database environment, as given by ZETA_TESTSUITE_DSN, but I - find no trace of what was originally intended.
- Add Makefile for my convenience
- Alter composer.json to reference fork/branched repositories; add database, database-schema, workflow dependencies
- Propagate the stored database node_id throughout the various structures
- Support the new workflow-execution flow with try/catch implementing begin database transaction with commit/rollback at the same place in the code
- Support adding the database constraint on parent_id, which means the value changes from zero to null
- Change the database table prefix. The value is hard-coded in options/database.php
- Adjust the workflow test case loader to use the vendor/ directory
- Provide sqlite memory database in absence of constant ZETA_TESTSUITE_DSN
- Adjust the canned schema to use the table prefix
- Marked a test as incomplete which now fails because we correctly use the database node_id. This means that the xml-stored version and the database-stored version will not be identical