Fixes #3368. Fix unit tests to dispose properly

[tig]

Fixes

• Fixes Fix unit tests that don't dispose View correctly. #3368

Proposed Changes/Todos

• Update API docs and conceptual documentation
• Remove the call to Application.Top?.Dispose in AutoInitShutdown.After. This will cause several dozen unit tests to fail. The fix for most of them is to simply add a top.Dispose () as the last line of the test.
• Change SetupFakeDriver to inherit from TestRespondersDisposed (and ensure Before/After call base). This will cause even more existing unit tests to fail. Here, the fixes will involve just disposing View objects the tests create but don't dispose.

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