ENH: build archive, add trans

Improved bootstrap.sh file to directly build the archive. Also added the trans file, so not other files are needed. I think bootstrap.sh should be renamed and all other files (except trans file) can be removed.

The archive is here: ftp://surfer.nmr.mgh.harvard.edu/pub/data/MNE/MNE-spm-face.tar.gz

cc @dengemann @Eric89GXL