Build 482 is released

1. Zlib is integrated for   nii.gz,  mgz, and nrrd support. Correspondingly 7zip.exe and DLL are removed.

2. NRRD file format is supported through File>Open Image  (where nifti etc). This is supported for the integer file reading. NRRD is very often used for ground truth storage (f.e. Duke database). Read  only.