Currently app extensions are treated as completely separate apps, and we may end up duplicating user frameworks (the Frameworks/* directory) between the app and any app extensions.

We should figure out a way to improve this.

Two potential ideas come up:

• A post-build msbuild target that looks for user frameworks in app extensions that also exist in the app container, and deletes them from the app extension if they're identical.
• Don't copy frameworks to the app for app extensions, but copy frameworks for all contained app extensions when copying frameworks for the container app.