Matt McCormick authored Oct 21, 2011 and Brad King committed Oct 24, 2011

This is an ITK specific check.  It is already implemented in
the ITK Utilities/Hooks/pre-commit script executed in the hook chain.

This should allow commiting when on the ITK release branch where .txx
files still currently exist.

Change-Id: I1115a2129beb89d6657d599aa6e72bb6515dfca3