Fix #2559: Make equivalencies work correctly with compose.
Add another compose-to-equivalencies example.
Fix tests
Default ``data_start`` to 0 in ``CommentedHeader``

fixes #2692
Made Latex/AASTex tables use unit attribute of Column for output
Remove support for Numpy 1.5.x
Reinstate something that shouldn't have been removed.
Re-word CHANGES entry.
Reinstate some of the workarounds for Py3 on io.fits
Support Pythons without bz2 support
Simplified units logic and updated test
Improved consistency of FK5 <-> Galactic conversion with other codes and with FK5 <-> FK4 <-> Galactic route.
Fix tests
Removed dict comprehension
Fix remaining tests
Fix frame attribute inheritance in SkyCoord.transform_to
Update CHANGES.rst
Merge pull request #3064 from mdmueller/table-units-latex

Made Latex/AASTex tables use unit attribute of Column for output
Update CHANGES.rst for #3064
Merge pull request #3054 from hamogu/fix2692

Default ``data_start`` to 0 in io.ascii ``CommentedHeader`` reader