Use MeshFileHandler to load dropped files
Use MeshFileHandler to load dropped files

This fixes #6

quillford/Cura,bq/Ultimaker-Cura,lo0ol/Ultimaker-Cura,DeskboxBrazil/Cura,fieldOfView/Cura,fxtentacle/Cura,totalretribution/Cura,markwal/Cura,ynotstartups/Wanhao,DeskboxBrazil/Cura,hmflash/Cura,Curahelper/Cura,fieldOfView/Cura,derekhe/Cura,ad1217/Cura,derekhe/Cura,hmflash/Cura,bq/Ultimaker-Cura,ad1217/Cura,ynotstartups/Wanhao,quillford/Cura,Curahelper/Cura,markwal/Cura,totalretribution/Cura,lo0ol/Ultimaker-Cura,senttech/Cura,fxtentacle/Cura,senttech/Cura