[Soc2014] Official meta API

This I guess is one of the issues that comes with standardising.
Now, we are treating all fields equally. Personally I think this is a great thing. Said this, the internals of Django sometime require some exceptions (just like admin dosen't like GFKs).
I personally would not like to have a flag like "not_supported" because it dosen't promote anything good.
If there have been some mistakes in the future (such as get_field() not being able to fetch GFKs) I propose to clean these up as much as possible, but once this API is release, there should not be any "2nd class" field types.