- Automatically write pixel type and dimension to parameter file from
image type at runtime
- Default parameter maps
- Lots of fixes

TODO: Superclass GetOutput() does not trigger Update() as it should

As of this commit the transformix filter executes correctly on
call to GetOutput(), but calling GetOutput on the elastix filter
does not trigger an Update() as it should

Previously, separate containers was used for fixed and moving images.
The ITK pipeline would be driven only by the first fixed and first moving images.
This commit introduces extra bookeeping so that all images can be added to the
ITK input container and split into seperate containers for elastix at a later
stage. This is necessary because only ITK input container is part of the
pipeline mechanism.

Another (and possibly simpler) solution would be override the Update() function
and check that all image containers are up to date. However, this places the
responsilibity of pipeline mechanism maintenance on us. It is probably better
to keep this upstream.

TODO: Test fails because of problems with setting up multiple instances
of xout in the same process

Interface related criteria can be handled in the MeetsCriteria in the
BaseComponent as well as the iterator over criteria, other (developer-user) specific Criteria are deligated to
MeetsCriterum per iteration.

Interface related criteria can be handled in the MeetsCriteria in the
BaseComponent as well as the iterator over criteria, other (developer-user) specific Criteria are deligated to
MeetsCriterum per iteration.

TFixedImage as the ImageSource template since the output image is
always resampled to the fixed image domain.

TODO: Fix 'error while setting up xout' error when running multiple
ElastixFilters in the same binary (see ELASTIX-56 in SuperElastix Jira)

All example components have the propertie ClassName as selection
criterium.

Moved ComponentSelector classes to ComponentInterface, moved Examples to
ComponentExamples. Made all Examples adhere to ITK factory functionality.

- Changed to namespace selx
- Combined componentbase classes and based it on itkLightObject
- Initial combination of example components
- Made templated ComponentFactory to replace all specific factories

Adds a stand-alone ITK filter that wraps the elastix library
in a fully pipeline-compatible process object. The original
library interface was deprecated in favor of direct use of
elastix internals in the filter's GenerateData() for more
control over pipeline inputs and outputs.

TODO: Support multiple fixed and moving images
TODO: Return TransformParameters

WIP: Segmentation fault when trying to access result image