C64.emu

What's New:

Update C64.emu to VICE 3.9

* EmuFramework: Add EmuApp::handlesRecentContent to allow the app to directly handle saving/loading recent content
* C64.emu: Rename "Apply Quick Settings & Restart" menu item to "Relaunch Content" and move above reset command
* C64.emu: Use different save state extensions for each core to prevent loading incompatible states
* C64.emu: Store recent content entries per-core