Stadiacast 1.2.0

A virtual gamepad on Linux, the controllers' live state as a document and as events for other
programs, a way to stop a receiver that runs in the background, and headset sound on Linux
that is what the computer plays.

Added

• A virtual gamepad on Linux: --gamepad uinput turns each controller into a wired Xbox 360
  controller for the games on the receiver's PC, through the kernel's uinput device, with
  nothing to install. SDL, which Steam and most Linux games read gamepads through, takes it
  for one, and a game's rumble comes back to the controller. The pad appears with the
  controller's first input and goes when the controller is switched off.
• GET /_input: what every controller is doing right now, in one small document: the state of
  its link, its address, battery and virtual pad, and the latest report with the buttons held
  by name, the sticks and the triggers. GET /_events sends the same document as server-sent
  events, one whenever something in it changes, for a program that shows or uses the input
  without reading the log.
• POST /_shutdown stops the receiver as Ctrl-C does, helper processes, headset streams and
  virtual pads included. It is taken over the loopback address only, so from the receiver's
  own computer, and is the way to stop a receiver that runs in the background on Windows.

Fixed

• On Linux, --audio-source system sent the microphone to the headset instead of what the
  computer plays, on systems without ALSA's PulseAudio plugin. It now records the default
  output's monitor through the sound server's own parec, on PulseAudio and on PipeWire, in
  the stream's own format, and also when the receiver runs with sudo.
• --audio-devices ended in a traceback on Linux when PortAudio could not reach a sound
  server. It says so in one line, and so does a device:NAME source in the log.