Merge pull request CommunityToolkit#629 from Microsoft/dev

Merging 1.2 to master

Merge pull request CommunityToolkit#618 from lukasf/dev

Fix DispatcherHelper open issues

Merge pull request CommunityToolkit#592 from Microsoft/finalpolishing

Cleaning last warnings

Update index.md

fixing copyright for packages

Merge branch 'CompositionFix' of https://github.com/Microsoft/UWPComm…

…unityToolkit.git

New readme image

Single commit of changes to fix master branch

This removes previously pushed AppPackages

Add new "PackNuGetNoBuild" target to build script