Prevent crash when encountering Icon? files on Max OS X. Refs #917.
Prevent crash when encountering Icon? files on Max OS X. Refs #917.

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