[#363] add level, count, surveyId to placemarkDto
[#363] Introduce surveyedLocaleCluster and surveyedLocaleClusterDao
[#363] introduce geocells methods

* add geocells property to surveyedLocale kind
* compute geocells when new surveyedLocale is created
* adds method populateGeocellsForLocale, which can
be used to bulk add geocells for existing data
* adds method to find locales that fit into a geocell
[#363] Put mergeNearby to false by default
[#363] Cluster surveyedLocale objects when created
[#363] Add surveyedLocaleClusterDao class to webapp-context
[#363] Method to create test locales, to test clustering
[#363] add geocells javascript library
[#363] Add CSS to place the marker images correctly
[#363] Remove country parameter from placemark REST call
[#363] Fix UTF-8 issue in flowDashboard.js
[#363] Add geocells.js to dashboard html
[#363] Method to bulk recompute locale clusters
[#363] Add creationSurveyId property to surveyedLocale kind

* We need this property to be able to filter on surveys later
* includes method for bulk updating old data
[#363] Remove google api reference in dashboard html
[#363] Dao method to list all locales with pagesize

* This is used in the bulk-update code for recomputing
locale clusters and in adding creation id to locales
[#363] Use Mapbox API to render maps
[#363] Rewrite maps code to work with clusters
[#363] Adapt placemark rest service to serve clusters
[#363] Don't show private data on public map