Attempt to calculate delta_ut1_utc when the attribute is accessed directly
More explicit setting of jd1,jd2 in _get_delta_ut1_utc
Add bug-fix entry to CHANGES.rst
Add support for OGIP format units.
Add warning that `Wcsprm` should not be used to get the original values
of keywords in the header.
Call `set` from within the WCS constructor.
Correct UT in calculation of TDB; closes #1938
Also update TDB, TCB in test done in documentation
Merge pull request #1939 from mhvk/time-correct-ut-in-tdb

Correct UT in calculation of TDB; closes #1938
Merge pull request #1925 from mhvk/time-delta-ut1-utc

Attempt to calculate delta_ut1_utc when the attribute is accessed directly
Add convenience class for comma-separated-values files

Read and write comma-separated-values files with
ascii.read(‘file.csv’,format=‘csv’)
ascii.write(table,”output.csv”,format=‘csv’)
Does not yet automatically recognize .csv extension
Add tests for CSV in io.ascii
Add CSV test file
Up Time's __array_priority__ to above Quantity's
Merge pull request #1940 from mhvk/time-array-priority

Up Time's __array_priority__ to above Quantity's
Add CSV option to documentation tables
Changed non-existent "self.matrix" to "matrix"
Fixed bugs in sphinx docs
Added regression test, logged changes
Move the binary installer background images to a new 'static' directory at the root of the source code for containing miscellaneous static files that do not necessarily have to live directly in the root of the project.