loader: get arXiv number from ADS?

[fschwenn]

To be discussed: For certain journals one could check ADS if they already matched the journal article to an arXiv preprint.

Expected Behavior

The program would construct the ADS-link (like http://adsabs.harvard.edu/abs/2017A%26A...603A.137M) for certain journals, check the ADS site for an arXiv number and add it with a source information to the record such that the matching in INSPIRE becomes trivial.

Current Behavior

At DESY we do this at the moment for 'Astron.Astrophys.' and 'Mon.Not.Roy.Astron.Soc.' as these are big astro-journales for which we do not get feeds but instead harvest web pages a while after an issue is completed such that ADS had time to match arXiv and journal article.

Context

This is mainly for the matching process.