sci-libs/itk-4.4.2-r1: fork from itk-4.4.2.ebuild
sci-libs/itk-4.4.2-r1: Add vtkglue use flag

Enable Module_ITKVtkGlue if vtkglue use flag is set. VtkGlue is used for
glueing an ITK pipeline and a VTK pipeline together.
sci-libs/itk-4.4.2-r1: Add doc use flag

Install doxygen documentation tarball if doc use flag is given.
Merge pull request #142 from shuber2/itk2

sci-libs/itk: add use flags vtkglue and doc