metadata representation from the solr index. This shall replace metadata
from the built-in database in the future.
- added the Solr-driven metadata into the search index of YaCy which
makes it now possible to run YaCy without the old metadata index. This
is a major stept forward to a full migration to Solr.
- a new database for url reference data ('seen links')
- a new database extending the references to the full url metadata
attributes set which shall replace the old metadata database if it is
finished
- migration help classes stub to use old and new metadata databases
simultanously
Michael Peter Christen