Issue #36: beginning work on trek precise tiles loading on map
Issue #36: doing some refactoring to add a LeafletMBTileLayerService to map Leaflet custom TileLayer with Cordova MBTilesPlugin
Issue #36: updating returned layer object structure, to be able to add more than one on leaflet directive parameters
Issue #36: removing tile loading at init step
Issue #36: deporting some logic into Leaflet plugin, because 2 multi-layers problems : angular-leaflet-directive cannot manage more than one baselayer AND mbtiles plugin was always using the same database, due to common mbtiles plugin instance for each layer
Issue #36: Removing no more used MBTilesPluginService
Issue #20: modifying test conditions for wifi download warning (previous code was test purpose only)
Issue #36: cleaning logs in Leaflet TileLayer plugin