[Insight-developers] removing some options from CMakeList.txt

[Luis Ibanez]

In order to facilitate ITK's inital configuration process
The following options are being removed from CMakeLists.txt files:

1) BUILD_AUXILIARY
    The directories in auxiliary already have dependencies that
    will prevent them from being built if the required libraries
    are not available (e.g. FLTK and VTK)

2) BUILD_FLTKIMAGEVIEWER
    This enable the built of FLTK classes that are used by examples.
    This will now be built if and only if FLTK is being found.

3) BUILD VTK_INTERFACE
    This conditions the built of the classes that illustrate how
    to link ITK and VTK.This will now be automatically build
    if VTK is found


The following variables are still confusing for first time
users:

    SEGMENTER_WRAP_TCL
    VTKITK_WRAP_TCL

Both are used by the SegmentationEditor. Maybe it could be
better to just have one option for building this example,
and require to have found VTK and Tcl. The current options
are in the WST.cmake file.

It could probably be reduced to BUILD_SEGMENTATION_EDITOR_EXAMPLE.




Luis