Clean legacy leaflet version dependency
 Added leaflet.draw dependency
Added leaflet.draw resources loading
Added several new events related to elfin lifecycle
Refacator events names to be more consistent and readable
Added events dispatching in elfin and card lifecycle (load/unload, update/delete)
Some small code cleaning
Code reorganization
Added observers for elfin lifecycle
Added observers for card lifecycle to detect current dispalyed elfin
Added draw layer and control to the map
Removed rectangle, circle draw shapes
Removed edit control
Added some comments
Organized draw events method structure
Refactoring
Removed "Remove" handler from draw control
Added latitude/longitude coordinates to swiss coordinates
Added elfin reloading before card destroy to inform observers of the current real state
Fixed issue with layers adding up by cleaning all layers
Add moving base point (only geographical)
Added elfin as extended property of the layers
Added leaflet.snap to help bind markers to markers (topological relation)
Added point update full logic