DOC: Fix GradientDescentOptimizer doc grammar.

Change-Id: I198601713ed573a824988ed678f5d1e66fc42252
BUG: Using consistent naming for Transform template name change.

All all changed added "Template" to the end of the class name.  Classes with
v4 in the name inserted "Template" before the "v4".  "Templatev4" ->
"v4Template" for consistency.

Change-Id: I3ede4d70a623e86bce78b088a43acaeb71c7dd1e
BUG: Remove unused QUASI_NEWTON_STEP_ERROR.

This StopCriterion that may have been intended for the QuasiNewton v4
Optimizer was never used.

Change-Id: Id00cbbc9dbd3a95b26ba7c2bbd6e15ae783dc09b
Merge topic 'QUASIStopCondition'

b7e1218 BUG: Remove unused QUASI_NEWTON_STEP_ERROR.
ENH: updating level sets sparse layer visualization

Make the corresponding class inherit from itk::VTKVisualizeImageLevelSet and
rename vtkVisualize* classes itk::VTKVisualize* to make it consistent with
other visualization classes.

Change-Id: Ie222cfa341c3c35c5e04d7f39db50e3a0d3ef7f5
Merge topic 'GradientDescentDoc'

c994191 DOC: Fix GradientDescentOptimizer doc grammar.
Merge topic 'Templatev4Name'

aa8f724 BUG: Using consistent naming for Transform template name change.
Merge topic 'LayersVisu'

d359d19 ENH: updating level sets sparse layer visualization