Prepare for 0.4.8
Add version badge to README.md
.travis.yml: Build both debug and release.
Fix build with VTK 6
Update NEWS
Fix Keywords entry in .desktop file

desktop-file-validate script reports a missing trailing semicolon
Fix build with VTK 5
Update NEWS file
Cleanup and split nifti2dicom

Split nifti2dicom into a static library and an executable and link
qnifti2dicom to the library to avoid building the same files twice and
reduce build time.
Update NEWS file
Release Nifti2Dicom 0.4.8
Merge tag 'v0.4.8' into debian

Nifti2Dicom v0.4.8
New upstream release (0.4.8)
Build with libvtk6-dev instead of libvtk5-dev and libvtk5-qt4-dev
Refresh nd-backport.patch and build with vtk5 in older releases