TyTools 0.9.0

New Features:

• Support Teensy 4 (caveat: no RTC programming yet)
• Support macOS Catalina
• Configurable per-board serial rate (useful for serial non-Teensy boards)

Main Fixes:

• Look less ugly on HiDPI screens
• Fix ugly "classic Windows" style in TyUpdater
• Fix extra empty lines in serial monitor in some cases
• Fix JSON format in tycmd list -Ojson (string escaping, array)