Fix integer overflow np.product
A few short docstrings in examples for issue #1414

In the spirit of encouraging docstrings in tests...
Add link to flymake-cursor.el in Emacs dev docs
Update matchsep.rst

This PR adds the missing distance parameters in a coordinate matching example.
Use the system monospace font in the docs
One slight tweak to the changelog formatting
Preparing release 0.4
Back to development: 0.5
Adding skeletons to changelog for next releases.
Merge pull request #2742 from larrybradley/patch-1

Update matchsep.rst
Merge pull request #2728 from jehturner/patch-1

A few short docstrings in examples for issue #1414
Merge pull request #2722 from jeanconn/add_flymake_cursor

Add link to flymake-cursor.el in Emacs dev docs
Added entry for misc doc updates to changelog
Fix memory leak in WCS reported in #2754
Add changes entry.
Allow for custom datatype names in votable

This should allow end users to workaround VOTable files that contain
invalid datatypes.

Also adds two datatypes seen in Vizier tables: "unsignedInt" and "unsignedShort".
Update docs about datatype mappings.
Add changes entry.
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