#930. Evolutions handleWebCommand should use DBPlugin from the app and not explicitly create a new BoneCPApi. Also, add the DB_CLOSE_DELAY parameter to all h2 URLs or, after evolutions are applied, the last/only connection will be closed and they will be lost.
Update migration doc with the need for the DB_CLOSE_DELAY in H2 URLs. Add a warning to DBPlugin if that param is missing. Remove the param from test Helpers as at test time, we probably don't want to maintain DB data across multiple tests.
#930. Only log the warning about H2 DB_CLOSE_DELAY in dev mode