refs #841: only perform custom link actions on manual clicks
refs #841: only perform custom link actions on manual clicks

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