Documentation of the CDS reader class updated
Merge pull request #2316 from bsipocz/fix_io.fits_links_in_docs

Introducing main-docs-only option for automodapi
General documentation updated with an example of the load of CDS tables using URLs
remove pickle file test
Merge pull request #2322 from mwcraig/fix-2312

Change sort of registered readers/writers to avoid comparing types
Add CHANGES entry
Added gaussian absorption model.
Applied review comments to use Gaussian1D methods.
Added test for GaussianAbsorption1D fit_deriv method.
Added changelog entry for #1945--originally this as added for 0.3.1, but the fix was never merged to the 0.3.x branch.
Minor whitespace fixes
Merge pull request #2098 from embray/changelog-fixes

Fix up use of API doc references in the changelog
Merge pull request #2270 from mhvk/quantity-subok

Quantity subok, and replace __quantity_view__, __quantity_instance__
Don't do expensive complex number handling if we don't have to.
Merge pull request #1461 from mdboom/wcs/docstring-generation-simplify

Simplify docstring generation in astropy.wcs
Add explicit test of passing in EarthLocation; doc(string) updates
Merge pull request #2331 from mdboom/unit/dont-complex

sanitize_scale: Don't do expensive complex number handling if we don't have to.
Merge pull request #2215 from pllim/gaussian-absorption

Add GaussianAbsorption1D
Mark SAMP HTTPS server tests xfail (see issue #2064)
Should somewhat fix or at least improve the situation reported in
https://github.com/astropy/astropy/issues/2305 by ensuring that the
method (_ImageBaseHDU.update_header) responsible keeping an HDU's header
in sync with the data it represents, also makes the necessary updates to
ensure that the header contains the correct BZERO value for
pseudo-unsigned integers.