Stop registering with payload autoloaders

The installer no longer adds the daemon to Payload Manager's or
ps5_autoloader's load order. It writes /data/tailscale/tailscale.elf, adds
the home screen icon and starts the daemon; starting it after a reboot is
left to the user. The daemon's status page and Uninstall no longer look at
autoloaders either.

docs/BUILDING.md

@@ -52,7 +52,7 @@ These folders are not in the repository.
 
 ```powershell
 # daemon payload: C launcher + Go program -> out\tailscale.elf
-.\tools\build-payload.ps1 -GoDir tsd -Name tailscale -Version 0.2.1
+.\tools\build-payload.ps1 -GoDir tsd -Name tailscale -Version 0.3.0
 
 # installer -> out\tailscale-installer.elf (embeds out\tailscale.elf)
 .\tools\build-installer.ps1