Add option for cell to access row data

Registered by Gal Margalit

Summary
=======
Add option for cell to access row data

Motivation
===========
Currently there isn't a mechanism for table cell to access fellow members cells' data.

Description and use case
====================
Example of implementation in Mistral Dashboard:

Tooltip of "state" column shows the "state_result" data,
screenshot in the link:
https://review.openstack.org/#/c/261839/

Doc Impact
==========
Affects documentation.

Current blueprint status
==================
Was discussed upon in the Horizon Drivers meeting: 02/17/2016.
I wanted to get feedback regarding my patchset implementation - design wise, and about the overall desired functionality.
As the requirement comes from Mistral Dashboard alone, as for time writing, it was decided not to have this option implemented, not until more developers will require such feature.
If anyone finds it interesting, please reply.

Blueprint information

Status:
Complete
Approver:
None
Priority:
Undefined
Drafter:
Gal Margalit
Direction:
Needs approval
Assignee:
Gal Margalit
Definition:
Obsolete
Series goal:
None
Implementation:
Needs Code Review
Milestone target:
None
Started by
Gal Margalit
Completed by
Rob Cresswell

Related branches

Sprints

Whiteboard

Gerrit topic: https://review.openstack.org/#q,topic:bp/add-option-for-cell-to-access-row-data,n,z

Addressed by: https://review.openstack.org/271771
    Added option for cell_attributes_getter to return row data

(?)

Work Items

This blueprint contains Public information 
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