1. NIFTI-4D: Corrected the each frame timing calculation using nim->toffset\nim->dt information.
2. Implemented a custom processing option for DICOM Open Folder dialog box. Rarely DICOM datasets have SeriesUID unique for each slice, so the option was introduced to parse them correctly.3. Defect fixed: In NIFTI file obtained from SPM (type FLOAT64) there were many entries with the value NotANumber, so this was making Firevoxel crash. Fixed by changing these values to 0, during the load.
