Fix #2559: Make equivalencies work correctly with compose.
Add another compose-to-equivalencies example.
Fix tests
Improve error message when ascii.read guessing fails
Added SkyCoord.to_pixels_wcs
Added test for SkyCoord.to_pixels_wcs
Describe how to test with a particular config value.
Fixed error in io.ascii on Mac
Added a --repeat option for testing
Changes Model.inverse to a property that can be updated to return a custom inverse model when available.  Updates existing models and tests, and adds a test of the new feature.
Fix reference in docstring
Add getitem to MaskedColumn to copy attrs for slicing
Update CHANGES.rst [skip ci]
Add Table-level test of changing MaskedColumn attr and slicing
Added repeat option to test()
Correctly detect and handle invalid input world coordinates.
Add CHANGES entry
switched to `to_pixel`
add cls keyword to pixel_to_skycoord
Added see also sections