Arrays merged

Good news everyone! ArrayField has been merged into django master. This will not be backported to the upcoming 1.7 release, but it will now be in 1.8. You can read the documentation. Let us know if you find any errors!

There are two notable areas which still need to be addressed with arrays, but the patch was large enough to review and merge without those as well. The first is improving its behaviour in the admin. I would like to provide an admin widget which uses the normal admin widgets for each field, starting with a given number but also being extended to arbitrary size by an "add" button on the page. This extension is rather difficult to implement at present because of most of the django admin widgets are not easily constructible from javascript. In order to do this well, a fairly significant overhaul of how the Django admin renders widgets such as the date/time widget and makes them interactive is needed.

The second area is indexing. While db_index=True will work on an ArrayField, it will create a btree index which is only useful for equality in this case. The correct index type is a gist index, but there is no way to tell Django this is what I need. This will require a refactoring of spatial_index in contrib.gis as well, and fits nicely within the work on custom indexes.

I think my next area to work on will be uuid fields, with larger primary key fields coming out as a corrollary. The interest here will be in supporting making fields other than AutoField be "auto" fields - using RETURNING to allow the database to calculate their values and return them.

For those interested, slides from my talk at DjangoConEurope are available online.