[Tubetk-developers] merged the RegistrationRefactoring stage branch

[Matt McCormick]

Hi,

As we previously discussed, I merged the RegistrationRefactoring
branch on the stage so that further changes can go through code review
and to prevent diverging from master.  The registration refactoring is
still a work in progress, but there was a lot completed.  Also
included were some ancillary fixes for VTK 6, ITK 4, memory leaks,
etc.  I'll be cleaning up any issues that arise on the dashboard over
the next few days.

Thanks,
Matt