BibIndex: new tag for address field, parent and author fields mapping

* Associates the `address` field to a single `371__%` tag instead of many
  `371__a`, `371__b`, `371__c`, ... tags
* Keeps other tags associated with the `address` field: `110__a`, `110__b`,
  `110__t`, `110__u`, `410__g`
* New `parent` field associated with tag `786__w`
* Associates `author` field with tag `786__w`

Signed-off-by: Federico Poli <federico.poli@cern.ch>

This pull request includes changes from https://github.com/inspirehep/inspire/pull/31