SciTools/iris — pull request #1403 by rhattersley (2014-10-20 10:33:12+00:00)
Title: Remove external use of `_data` attribute.

The data API of the 2D field formats is currently a bit of a mess, with `_data` being accessed from outside the classes in order to provide to deferred loading. This PR attempts to improve matters by borrowing the `data`/`lazy_data()` API from the `Cube` class.