Display disease occurrence point details in side panel

This branch also includes the implementation of
- a "layer switcher" sentence with pull down menu for the logged in user's disease interests
- cluster markers with leaflet plugin
- knockout viewmodels (for layers on map, and the selected disease occurrence point)

NB. Shapefile must be manually imported to DB, and local GeoServer configured and running, for base layer to be displayed. An expert's disease interests must be manually inserted to DB (ie add rows to ExpertDiseaseGroup table) for drop down list to be populated, and any points to be displayed.