Enhancement - Validate DB Settings During Add

[MikeD096]

Application should validate host/user/pass/DB settings when adding DBs to be backed up.

The application should use the parameters entered and attempt to at least connect to the database to validate the settings. In its current release, a user can enter incorrect information and the application states "Success" and adds it to the list. The end user would not catch the error until the application later attempted to run the backup and fails, or if the user attempts a manual backup.

If validation fails, present the reason for the failure (eg "Bad user/pass", "invald database", etc)