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.
- search request are now made using a map boundary
- search results are only computed for the map boundary
- the number of results is adopted to the results in the visible range
- added a double-buffering for the search result markers
- added a search query option for the search results:
/radius/<lat>/<lon>/<radius>
