MainLauncher: Remove Thread.destroy() - n/a on Android ..
Fix ActivityLauncher/MainLauncher .. and make adb-launch-main more suitable

- ActivityLauncher
  - no finish() from onDestroy()

- MainLauncher
  - finish activity after returning 'main()' returns
  - no finish() from onDestroy()

- adb-launch-main:
  - Clear logcat
  - Wait until activity is stopped
  - Dump logcat to local logfile