* Update core to VICE 3.9
* Rename "Apply Quick Settings & Restart" menu item to "Relaunch Content" and move above reset command
* Use different save state extensions for each core to prevent loading incompatible states
* Store recent content entries per-core
* Add Options -> Frame Timing -> Low Latency Mode to keep the emulation thread in sync with the renderer thread to prevent extra latency, turned on by default but trying turning off in case of performance issues