Revisit event handling when Excel is OLE embedded

We should write some guidance for issues that appear when Excel is running embedded in another application.

Some links:
* https://gist.github.com/crazyfool2100/1079987
* http://olappivottableextend.codeplex.com/discussions/271174
* https://blogs.msdn.microsoft.com/vsofficedeveloper/2008/04/11/excel-ole-embedding-errors-if-you-have-managed-add-in-sinking-application-events-in-excel-2/