- Require FOREGROUND_SERVICE permission (necessary for Android 9)
 - Use an activity (instead of a broadcast receiver) as entry point,
   so that the intent is always allowed by Android (#112, #117, #146,
   #150, #151, #161, #178, #180, #187, #190, #199, #227, #242)
 - Fix cleanup race condition in Java relay server (#154)
 - Workaround rust/mio issue on MacOS (#136)
 - Add command-line option to use a custom port (#210)