Revert "A little cleanup from the Documentation branch merge to remove references to the AssemblyInfo file(s) from the project files since the files are non-existent."

This reverts commit f887af21162347612feb0fa1efb7fa29010a4e6f.
Add dummy assemblyinfo files to satisfy VS
remove dependency on custom targets files (assemblyinfo now generated by build_universal.sh; nuget run by build_universal.sh)