Forced rebuild because of merge issues with astropy_helpers

* The commit history where astropy_helpers accidentally got
  modified is making rebasing off of master really messy, so
  rebuilt from current.
* CHANGES.rst not modified, so this is *not* ready to go.
  Should wait on 0.4 to shake out before updating that.
Update CHANGES to include cosmology clone operation

* Placed in 1.0 section
* Closes #2592
Rewrite Distance initializer so it can take lists of quantities.
Put back in automatic unit selector for distmod with array support
Merge pull request #2592 from aconley/copy_cosmo

Making slightly different cosmologies is awkward
Merge pull request #2261 from mhvk/distance-lists-ok

Distance should accept lists of quantities with different units
typo fix: arcseconds->milliarcseconds


[ci skip]
Expand locale known issue
Merge pull request #2760 from astrofrog/more-known-issues

Expand locale known issue
Describe bounds checking at toplevel of docs.
Fix formatting error that causes PDF/LaTeX docs to not finish.
Don't put all user documentation under the "what's new" heading in LaTeX docs.
Merge pull request #2763 from mdboom/wcs/bounds-check-doc

astropy.wcs returns nan when galactic longitude >= 180 degrees
Merge pull request #2764 from mdboom/docs/latex-fixes

LaTeX doc build fixes
Merge branch 'omega_b' into explore-conflict

Conflicts:
	CHANGES.rst
	astropy/cosmology/tests/test_cosmology.py