Nightly build

Continuous build 0.1.2-nightly.1612d5c of master at 1612d5c.

Take TomLabs.AutoUpdate from nuget.org instead of the submodule

The shared self-update library is now a PackageReference to
TomLabs.AutoUpdate(.Avalonia) 0.3.2 from nuget.org; the lib/TomLabs.AutoUpdate
submodule and its solution entries are gone. Docs no longer ask for
--recurse-submodules.