File io: avizo file loader and numpy converter

avizo_io.py file loader tool fully functional for ASCII and BINARY file formats. Still requires work to enable loading of AmiraMesh-Zip file format data sets.
In particular, I need suggestions for tests to include in the test_avizo_io.py file.
Also, write functionality is still on the TODO list.
All the print statements have to change to logging

https://github.com/NSLS-II/NSLS2/blob/master/doc/resource/dev_guide/logging.rst