Revert "BUG: Do not register IO factories for testing within ITK"
Revert "BUG: Do not register IO factories for testing within ITK"

This reverts commit a27a5587c4489cd49d1f93a9b1c579391fb262a1. See
conversation in GH-207.

SimonRit/RTK,SimonRit/RTK,SimonRit/RTK,SimonRit/RTK