Tomlm/fix401 merge master (microsoft#4791)

* fix success to use status==TaskStatus.RunToCompletion instead of .IsCompleted

* merge translation

remove configure awaits (microsoft#4582)

* fix OAuth with emulator and no credentials

* remove configureawait(False), as we need to keep the callers context for callbacks

* bump version to 3.15.2.2

fix OAuth with emulator and no credentials (microsoft#4570)

bump versions

Published 3.15.0 for //build

Bugfix/handle empty stack (microsoft#4549)

* Added a check for count before poping from stack.

* Fixed test to reflect actual expected exception.

Enumerate missing resources when throwing MissingManifestResourceExce…

…ption (providing notice to developers of which resources are actually missing). (microsoft#4374)

Patch nuspecs and bump versions (microsoft#4335)

* cleanup nuspec files

* bump version

* bump connector version

fixed race condition when refreshing access token. (microsoft#4084)

Adds NuGet.config for samples, ensuring they restore to the correct d…

…irectory, and updates package references for AnnotatedSandwichBot. (microsoft#3929)