Enhance the ProjectUpdateResource for easier integration

[zzgvh]

Commonsites want to use the API to populate their site with project updates and we have a similar use case on akvo.org itself. However it's hard (impossible without an API key) to access all data that is publicly available on the web pages of updates, specifically the user's full name and organisation affiliation.

[adriancollier]

Even with a Key it's only possible to reach this information if the user is actually within their organisation.

I would prefer not to open the API so all of this information is public, but to promote the use of an API key, and then also ensure that all the necessary data is then available to them.

So, we should try to include this kind of feature improvement with the Network Partner option we are looking at here: #247

[zzgvh]

We could easily limit the extra fields added above so they're only available if you access the API with a key.

[adriancollier]

I think we need to do some more spec before we push the API key as there seems to be some difference in the impact for and against.

In the meantime, @zzgvh if these items are finished, can you please merge them into Develop so we can view the result?

[KasperBrandt]

I think this issue is already covered in #463. The only thing is that '_extra' needs to be added in the link, e.g. http://rsr.akvo.org/api/v1/project_update_extra/4332/?format=json.

@zzgvh What do you think, can we remove this issue (and branch)?

[zzgvh]

Yes, the project_update_extra resource should cover the above needs too. I talked to @stellanl yesterday and the Up app needs more data that should be added to project_update_extra. The same goes for the needs of the data pulled to akvo.org. I'll document it in #463.

[KasperBrandt]

Merged in #591