Published paper

This version corresponds to the text to be published in Astronomy and Computing and now available online at http://dx.doi.org/10.1016/j.ascom.2014.09.001.

Submitted to astro-ph

This is the text of the manuscript accepted for publication in A&C as uploaded to astro-ph on 2014-09-16. This also matches the text sent to Elsevier for typesetting.

submitted-2014-07-22

Revised version submitted to A&C 2014-07-22.

Submitted to Astronomy and Computing

submitted-2014-04-25

Submitted to Astronomy and Computing