SciTools/iris — pull request #1114 by bjlittle (2014-05-02 09:09:47+00:00)
Title: Deferred PPField attributes.

This PR provides a performance optimisation to the PP and FF loading pipeline to the point when a `PPField` is created only.

It offers a loading speed-up of approximately 75% by implementing deferred `PPField` attribute creation and avoiding the use of expensive convenience PP attributes such as `stash` and `lbpack` where possible.