DEV: Created new branch focused on net_CDF file IO

Commits to this branch focus solely on net_CDF file-IO.
The netCDF file-IO functions are being stripped from the original
fileops.py collection of image processing file read/write functions.
DEV: Intermediate netCDF dictionary creation step

Had to commit in order to access the avizo_io.py file
which contains pertinent functions for processing and
cleaning up the metadata dictionary.
DEV: Started adding test function for netCDF_io
DEV: Added simple test function for net_cdf_io.py
DEV: Updated and tested the load netCDF function.

Thus far this only includes file loading. Eventually I need to add
the file save functionality.
DEV: Changed file load step to use context manager
Merge branch 'master' of github.com:NSLS-II/NSLS2 into net_cdf

Conflicts:
	nsls2/core.py
UPDATE: Removed .directory and updated .gitignore
Merge branch 'master' into net_cdf

Conflicts:
	nsls2/core.py
Merge branch 'master' into net_cdf
DEV: Added netcdf4 to conda recipe
DEV: pacified netCDF test function since it requires binary data set
BUG: removed dummy test function reference to test data.

This reference was causing travis to fail.
DEV: removed xr_data class from core.py
DEV: Added TODO statement for addition of test func after writer func

After writer function is written then test functions will be added
test will be: read-->write-->read, compare files.
Merge branch 'master' into net_cdf

Conflicts:
	nsls2/core.py
	nsls2/io/avizo_io.py
	nsls2/tests/test_avizo_io.py
	nsls2/tests/test_data/avizo/header/smpl_avizo_header.txt
Merge pull request #133 from giltis/net_cdf

netCDF file loading function