Adjust build target script to write new version numbers.
Adjust build target script to write new version numbers.

- Bundle version looks like 0.7.0.29 (major.minor.patch.commit)
- Short bundle version looks like v0.7.0-29-g37365c7

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