Add a point to coding style docs to follow existing subpackage style [skip ci]
Simplify wording and remove implication of 'preferences' [skip ci]
Make a single unique csv reader/writer function
Fix error due to DISPLAY variable and interactive Matplotlib backends
Remove CHANGES entry, since this bug was only in master and never released

[skip ci]
Merge pull request #3189 from hamogu/fix3090

io.registry: '.csv' is not longer sufficient to select reader.
Merge pull request #2967 from taldcroft/docs-follow-style

Add a point to coding style docs to follow existing subpackage style
Set matplotlib to Agg backend
Fix test for default value of RADESYS
Made ordinary and fast readers store comments in Table meta
Handled meta assertions in testing, fixed empty table issue
Removed comment regex from captured comments
Added doc section for comments/metadata and logged changes
Merge pull request #3246 from mdboom/wcs/fix-default-value-radesys

Fix test for default value of RADESYS
Fix to enable partial support for models that have more outputs than
they have inputs, at least in the most basic cases.  This sort of works
the same as how models with more inputs than they have outputs work,
which is that each input is not necessarily directly tied to each
output; instead all outputs are just assumed to have the same
dimensions, which are determined from the result of broadcasting all
inputs with all parameters.

In the future there may be more ways for individual model
implementations to control this (besides outright overriding
prepare_inputs and/or prepare_outputs).

This provides an alternate to this PR:
https://github.com/embray/astropy/pull/12
Add changelog entry.
Merge pull request #3248 from mdboom/misc/set-matplotlib-backend

Set matplotlib to Agg backend
Fixed up doc changes and test
Merge pull request #3222 from mdmueller/meta-comment-lines

Made ordinary and fast ASCII readers store comments in Table .meta
Merge pull request #3250 from embray/modeling/handle-more-out-than-in

Modeling/handle more out than in