[Snek] [keith-packard/snek] 8555dc: snekde: Make autobaud detection fancier

[Keith Packard]

  Branch: refs/heads/main
  Home:   https://github.com/keith-packard/snek
  Commit: 8555dcd0f0295e725dcec528ea6d8ed579a1e07b
      https://github.com/keith-packard/snek/commit/8555dcd0f0295e725dcec528ea6d8ed579a1e07b
  Author: Keith Packard <keithp at keithp.com>
  Date:   2022-04-09 (Sat, 09 Apr 2022)

  Changed paths:
    M snekde/snekde.py

  Log Message:
  -----------
  snekde: Make autobaud detection fancier

Put the autobaud code in a separate thread. Try it twice; once after
100ms and once after another 1.5 seconds to allow devices without boot
loaders to start quickly while still supporting devices with boot
loaders that delay for 1.5 seconds.

Signed-off-by: Keith Packard <keithp at keithp.com>