refs #1341: handle MBTiles opens with a bit more info
refs #1341: handle MBTiles opens with a bit more info

Teino1978-Corp/Teino1978-Corp-tilemill,mbrukman/tilemill,paulovieira/tilemill-clima,nyimbi/tilemill,tilemill-project/tilemill,nyimbi/tilemill,paulovieira/tilemill-clima,Zhao-Qi/tilemill,fxtentacle/tilemill,mbrukman/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,paulovieira/tilemill-clima,nyimbi/tilemill,MappingKat/tilemill,nyimbi/tilemill,florianf/tileoven,mbrukman/tilemill,tizzybec/tilemill,fxtentacle/tilemill,MappingKat/tilemill,tilemill-project/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,MappingKat/tilemill,MappingKat/tilemill,Zhao-Qi/tilemill,tizzybec/tilemill,Zhao-Qi/tilemill,fxtentacle/tilemill,mbrukman/tilemill,florianf/tileoven,Zhao-Qi/tilemill,fxtentacle/tilemill,paulovieira/tilemill-clima,fxtentacle/tilemill,mbrukman/tilemill,tizzybec/tilemill,Zhao-Qi/tilemill,MappingKat/tilemill,tizzybec/tilemill,tizzybec/tilemill,tilemill-project/tilemill,nyimbi/tilemill,paulovieira/tilemill-clima,florianf/tileoven,Teino1978-Corp/Teino1978-Corp-tilemill,Teino1978-Corp/Teino1978-Corp-tilemill