Python Serial Monitor with Time Sync

[leoyinjou]

adapted @ZulNs Python-based Serial Monitor (https://github.com/ZulNs/SerialMonitor) to allow all necessary functions:

1. send and receive in serial monitor via serial port (just like Arduino IDE's built-in serial monitor)
2. automatic time sync handling in background (just like the Processing sketch)
3. manual time sync via a GUI button (just like the Processing sketch)

[PaulStoffregen]

I'm a little nervous about including the compiled bytecode. Arduino has a policy against libraries including PC executables. Even if they allow this now, it could be a potential problem in the future if they continue to tighten the rules about extra stuff in libraries installed by their library manager.