Use of Apache Solr to provide server side map marker clustering for StoneSoup (https://github.com/datacommons/stonesoup) as used in production by http://solidarityeconomy.us (StoneSoup nsf_us_solidarity_standalone branch).

Exists as a seperate repository with the idea that the relevant Apache Solr java code could be useful to other sites that want clustering on the server side. Eventually the idea is to have the StoneSoup specific version in the stonesoup branch and the generic version in the master branch, but for now up to date code is only found in the (default) stonesoup branch.

Considerable inspiration taken from https://www.drupal.org/project/geocluster http://dasjo.at/thesis