gzip support in dream3d file format

We develop a tool that outputs synthetic microstructures directly as a *.dream3d data file, and after a bit of debugging, I realized that it was the HDF standard compression of datasets I started using a while back.

I see a drastic decrease in file size with a simple gzip (default compression) turned on (over 50 times smaller!), so it would be a shame if it could not be supported in DREAM3D.