AltexaBackup : Engine parameters check

Up until now, when creating a new job, the wizard would check with the different engines (backup and storage) each parameter to see if the value was OK with the engine.

This is all well and good, but not sufficient.

Imagine an FTP storage engine. It's a good idea to check that the host name entered does actually exist, but it makes more sense to check if we can connect with the username and password entered to the hostname on the port specified. This needs access to all four parameters at once, which wasn't available up until yesterday.

Now, while still checking individual parameters as before, there is a final check of all parameters together at the end.

Of course, an engine can implement or not either of these checks - deciding whether to check individual parameters or the whole parameter set. Or both. Or neither.

This weekend I also implemented the option of an engine requiring no parameters. This is true for the 'Copy Backup' backup enigne, which used to ask for a 'job name' field - which has no place in there at all. So I took it out, and the engine now requires no parameters. It has broken something in the backup worker though. Will have to look into that.