DOC release notes add assert_frame_equal checks index and column names
Appended to release notes re #2964.  
I put it in "API changes" (not sure if that is optimal but I wasn't sure where else it would fit).

hold off on merging for just a bit

going to put up a PR to fix index name propagation

so @hayd u might be able to some of the checks back on 
 This PR is just a DOC update and only changes `release.rst`.

Excellent to your PR, there are a few index/column name bugs/features to work through. Let me know which you are hitting and perhaps I can help on some others.

Weirdly, travis is broken on LOCALE build (presumably it is in master too):

```
FAIL: test_to_csv_moar (pandas.tests.test_frame.TestDataFrame)
```
 @y-p I _think_ it's one of your last commits fails on travis. (Or did you just fix it?)
 I think it's been there for a while and just didn't register. I just added
slow tests to LOCALE_OVERRIDE a couple of days ago on jeff's prompting.
Pretty sure I just pushed a fix for it 5 minutes ago, skipping some tests 
until  https://github.com/pydata/pandas/pull/3173 gets merged. float precision issues.
