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.
writings to the Metadata-DB are now also done to solr. This includes
metadata transfer during search and rwi transfer.
The new/added solr fields are:
## time when resource was loaded
load_date_dt
## date until resource shall be considered as fresh
fresh_date_dt
## id of the host, a 6-byte hash that is part of the document id
host_id_s
## ids of referrer to this document
referrer_id_ss
## the md5 of the raw source
md5_s
## the name of the publisher of the document
publisher_t
## the language used in the document; starts with primary language
language_ss
## an external ranking value
ranking_i
## the size of the raw source
size_i
## number of links to audio resources
audiolinkscount_i
## number of links to video resources
videolinkscount_i
## number of links to application resources
applinkscount_i