COMP: return will never be executed after exception thrown.

For:

  /Users/builder/external/ITK/Modules/IO/Mesh/src/itkOBJMeshIO.cxx:526:5:
  warning: 'return' will never be executed [-Wunreachable-code-return]

Change-Id: I8d3c7f95b747919050a6ba7ed45c5433f4d5acdb
ENH: bump to latest scifio-imageio

Updated the SCIFIO-ImageIO to fix a pixel type detection error. It
seemed that the returned pixel type was clashing with the
UNKNOWNCOMPONENTTYPE constant, causing an unknown component error to be
thrown erroneously.

Change-Id: I8f691f82da9288709e48626dd13d102d9df15bff
Merge topic 'exception-return'

6a54cbb3 COMP: return will never be executed after exception thrown.
Merge topic 'fix-pixel-type-detection'

9f6f245a ENH: bump to latest scifio-imageio
ENH: Add RegularStep gradient optimizer to ITKv4

We probably do not need this optimizer technically; however, having such
an optimizer is the preliminary step to convert "ImageRegistration1"
example to ITKv4.

Using ordinary GradientDescentOptimizerv4 does not provide convergence
for the example 1. Also, the results generated by other v4 optimizers
(e.g. GradientDescentLineSearchOptimizerv4) show a very fast
convergence, and they are not suitable for graphical interpretation of
the registration process that is necessary for the educational purposes.

Change-Id: I547f58f776952aebaa7d36ac2dd1540406617268
ENH: (ME) Convert the ImageRegistration3 example to ITKv4

Change-Id: I96b3e32e41aa27172c819e24243858c933538e40