Ox library data import

This should have been split in two really as we have the following:
1) extend POI with a dict of "meta" which represents k/v from Solr if they start with a specific prefix (e.g. "meta_"), the representation will add these fields (we might need to use this for transport in the future).
2) import library data, and add relevant data to the index with fields starting with "meta_library_*"