preparing for NIfTI support in v2

v1/libtpcimgio/img_nii.c

v2/imgutils/imgformat.c

v2/libtpcimage/image.c

v2/libtpcimage/imageio.c

v2/libtpcimage/imagenii.c

v2/libtpcimage/imagesif.c

v2/libtpcimage/libtpcimage.c

v2/libtpcimage/test_imagenii.c

v2/libtpcimage/test_tpcimage.h

v2/libtpcimage/tpcimage.h

v2/libtpcnifti/CMakeLists.txt

v2/libtpcnifti/analyzeio.c

v2/libtpcnifti/libtpcnifti.c

v2/libtpcnifti/niftiio.c

v2/libtpcnifti/niftiname.c

v2/libtpcnifti/test_niftiname.c

v2/libtpcnifti/test_tpcnifti.h

v2/libtpcnifti/tpcnifti.h