Moved basic JTS field stuff into V-Leaflet project

PointField is now implemented with basic V-Leaflet API and the implementation is drawn back to V-Leaflet. JTS fields based on Leaflet.Editable can now be based on the same base classes and basic GIS apps that only have point types, can now live with V-Leaflet alone.
fixed indexing  bug
Added a small hack to enable Leaflet.Editable by default in editors with map init parameter
Fixed Polygon setter with holes
[maven-release-plugin] prepare release v-leaflet-0.6.1
[maven-release-plugin] prepare for next development iteration