Drag'N'drop improvements

[mbredif]

Good job on the new drag'n'drop example !

Here are some suggestions for improvements for the drag and drop example #1159 :

• render geojson points (for example, I do not see the point of this geojson)

• register both json and geojson for geojson files (most geojson files have a json extension)

• register zip files and recursively add its contained files

• register shp files (all dependent files such as dbf being required to be dropped at the same time or within the same zip file) feat(parser): add a shapefile parser #1056

• register geotif feat(parser): add a TIFF parser using utif #1131