Generate the docstrings in _wcs.so using character arrays rather than
string literals.  This is (reportedly) more portable and avoid the
copying nonsense we did before.
Changing FITS table write function to have default value of Nan for float type cols
Changing default value for float columns from 1e20 to Nan in fits table write function
Changing the float comparison for filled value to np.allclose to enable Nan masking for float32 as well. Also added test cases for float64, and float32
Removing unnecessary comment
Rebuild from fresh master since rebasing was failing horribly.
Extra - got into title for 0.4
Support multiple and divide on angles.
Add link to Simple-Cone-Search-Creator to VO docs
Log to stderr by default
Added Celcius and Fahrenheit to units.
Fixed Celsius typo. Moved Celcius from imperial to si. Added change log and test.
Removed Celsius from si and cgs bases. Fixed failing tests.
Fixing io docs links for #1221
Change initialization of NDData arithmetic result to include keywords in constructor
Initialize result with keywords in constructor call
Add note to docstring indicating that flags are set to None

This is not a change in behavior in convert_unit_to, just indicating in the doctoring what is being done.
Add CHANGES.rst entry

Closes #2300
added width to various kernels
At @embray's suggestion, log INFO (and less) to stdout, and everything
else to stderr.  Also cleans up the USE_COLOR setting.