- Support the latest OS versions
- Improve stability

- Support the latest OS versions
- Improve stability

・Improve latency
・Add timestamp into outgoing MIDI messages
・Fix that the last MIDI connection was not reverted
・Improve Musical-Typing behavior
・Fix that MIDI output note velocity was invalid when played on-screen keyboard

Added new `Touch Sensitivity` feature. When the keyboard is played hard, an attack sound is added. Also, you can select how to switch sound as follows:
・Normal (Attack Sound Disable)
・Hard (Attack Sound Enable)
・Switching with Velocity
・Switching as Random

Added the new battery-saver feature. It monitors midi inputs when the app is in the background and stops the synthesizer if no MIDI inputs for 5 minutes. Of course, the synthesizer will be reverted when the app is moved to the foreground.

Fix the case that UI was broken