Fixed bugs related to ZLIB decompression and window size.
Divided the images module into separate MRC and utilities modules. Added a metafile module for MHA/MHD files. No longer uses SimpleITK for anything. The imsave and imread functions support MHA/MDA files now.
Updated utils.py to have more comments and for check_reqs to no longer check for SimpleITK since it isn't needed anymore.
Removed testing code from metafile module.
Combined mrc2png/mrc2mha into mrc2stack and png2mrc/mha2mrc into stack2mrc. This is possible due to the new custom metafile module.
png2mha was changed to conv_img since it now supports inputs and outputs of both SciPy and MHA/MHD formats.
Updated TODO list
Updated README