Version 1.0.0-beta.4

Change log entries for this release:

• add a control for master volume
• support loading SBI instruments
• support the Non session manager
• fixed a case when the state loading fallback would fail because of a bad initialization sequence
• fixed the editor state after closing and reopening under certain hosts
• allow to reload a saved bank which has no melodic banks or no percussive banks
• add an ability to delete entire banks
• memorize the instrument directory between uses
• update the bank collection for OPN2