Remove ChangeLabelImageFilter

This filter uses an std::map to bulk change labels in an image, there
is not appropriate interface for this.
Ignore Direction cosine parameters
Remove self test registration since it doesn't work
Move camel case regex to class scope

This improve efficiency by no recompiling the regular expression for
each filter.
BUG: ignore TypeError due to printing non-printable chars

Issue SimpleITK-210, printing char pixels as ASCCI not as numbers, in
Slicer's python environment this is causing a TypeError, which can be ignored
BUG: Process events to update status label before filter execution
Adding Slicer specific json for CastImageFilter

The SimpleITK CastImageFilter is manually written in SimpleITK and
does not have a json file. This file was written just for Slicer's
GUI.
BUG: ctkCoordinateWidget produces float string format use float

For converting to index coordinates, first convert to the float format
because int can not handle scientific notation.