Dbrequests

- dbrequests.mysql
- More stable and reliable Version of sync_diffs mode for sending data.
Respects scarce resources on the mysql server.

- dbrequests.mysql
- bugfix of 52

- dbrequests.mysql
- HOTFIX 51: Bug with latest datatable version

- dbrequests.mysql
- creating temorary removing partitions and system versioned from temporary
tables.
- new mode for send data: sync_diffs: update differences and delete
deprecated rows.
- new mode for delete data: in_delete_col: mark rows to delete, then delete.
- bugfix for temporary tables: now properly removes tables.

- dbrequests.mysql
- bugfix for upstream bug in mariadb: sending diffs needs persisten tables
instead of temporary.

- dbrequests.mysql
- bugfix in send_data with mode [update|insert|replace]_diffs: same as 36