Sections support

[kwent]

Following those issues #460, #362.

I hacked the library to support a plain JS object ( with a deep of 1 ) in addition of an array resulting the table to cut sections (multiple tbody) for each keys.

Final result is:

Data format is now:

const products = { categoryA: [ { id: 1, name: 'Item 1', price: 1000 },
                                { id: 2, name: 'Item 2', price: 2000 }
                               ],
                   categoryB: [ { id: 3, name: 'Item 3', price: 3000 },
                                { id: 4, name: 'Item 4', price: 4000 },
                                { id: 5, name: 'Item 5', price: 5000 }
                               ]
                 };

Demo file is here : https://github.com/kwent/react-bootstrap-table/blob/sections/examples/js/sections/demo.js

It's only tested with my use case. (Simple table with cell edit enable without breaking current features).

I don't think it's ready to merge but i think we should keep improve this PR to support all feature around a JS object. (checkbox untested, sort untested etc...)

[AllenFang]

That's cool, I'll check this out :)