Moved CodeGenerators to VisualStudio Project and retired Single File Generator (OnItemSave will pick it up)
Copyright notice
Reorganized pMixins.VisualStudio namespaces
Keep a reference to SolutionOpening Task to ensure HandleProjectItemSave doesn't run until Solution is parsed
Solution doesn't need to be built to warm caches, OnItemSaveCodeGenerator will do it
Repurposed VisualStuioEventTestBase as MockSolutionTestBase
Added functionality for CodeGeneratorResponseWriter to add code behind to Project
Added mocked methods to handle new ProjectLoaded methods / FileWrapper methods
New Tests
Improved logging