id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
324099923,MDExOlB1bGxSZXF1ZXN0MTg4Nzk1OTE3,2151,Plot labels use CF convention information if available.,2448579,closed,0,,,6,2018-05-17T16:36:04Z,2018-06-02T00:53:14Z,2018-06-02T00:10:26Z,MEMBER,,0,pydata/xarray/pulls/2151,"Uses attrs long_name/standard_name, units if available.

 - [x] Closes #2135, #1630, #1787
 - [x] Tests added (for all bug fixes or enhancements)
 - [x] Tests passed (for all non-documentation changes)
 - [x] Fully documented, including `whats-new.rst` for all changes and `api.rst` for new API (remove if this change should not be visible to users, e.g., if it is an internal clean-up, or if this is part of a larger project that will be documented later)

This PR basically uses @rabernat's `label_from_attrs` in #2135. 

Examples:
![image](https://user-images.githubusercontent.com/2448579/40190529-668475e0-59bc-11e8-8e03-879193082ec1.png)

![image](https://user-images.githubusercontent.com/2448579/40190494-4fdf439c-59bc-11e8-8b78-2a19b64d1a06.png)

![image](https://user-images.githubusercontent.com/2448579/40190445-35385dd0-59bc-11e8-82c9-389e9143fc34.png)
![image](https://user-images.githubusercontent.com/2448579/40190462-3d6a902c-59bc-11e8-809b-c0763474664c.png)
![image](https://user-images.githubusercontent.com/2448579/40190487-49ce18fc-59bc-11e8-895a-e4b518ceadc5.png)


I also changed the way histograms are labelled
**Old:**
![image](https://user-images.githubusercontent.com/2448579/40191183-e97235d6-59bd-11e8-8817-6e30564c6670.png)


**New**:
![image](https://user-images.githubusercontent.com/2448579/40191190-ee9c1f04-59bd-11e8-81fb-54c4192f51b0.png)


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