2.4 various fix

First step for future release 2.4.13 including already:

- fix when the update of the database schema is not done (regarding to the new HostConfig table) in order to be backward compatible
- fix for filename (or path) containing blank character, thus introducing a change in the protocol. However this change is made to be transparent and therefore should not involved any issue in the backward compatibility. Setting -Dopenr66.usespaceseparator=1 will revert to old mode, but then not allowing to have space in name.