add support for integrated database schema migrations

added the "initprovider" command to initialize the database structure.
If we change the database schema the required changes will be checked
at startup and automatically applyed.

sql/mysql/20200208.sql

@@ -0,0 +1,10 @@
+BEGIN;
+--
+-- Create model SchemaVersion
+--
+CREATE TABLE `schema_version` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `version` integer NOT NULL);
+---
+--- Add initial version
+---
+INSERT INTO schema_version (version) VALUES (1);
+COMMIT;