Revert "Bump nrefactory"

This reverts commit 00cfd55ab8edfada90ed01049857295af29d4b5d.
Revert "Bump NRefactory."

This reverts commit a6b45473f4bb7b69ac665babf1295ed3ed044115.
Revert "Track NRefactory API changes."

This reverts commit 186ce8a0d072bea3a97bd45a6060edc4eff12d9f.