Support for export to binary STL.

Binary STL shaves file size down quite a bit, for example a recent random file went from 2.2mb to 714kb. For more savings, ZIP on the binary STL shaves an addition 1/3, which takes the same file down to 270k. Use ZIP.js, JSZip or another option to handle this last step.
STLBinaryExporter
Merge remote-tracking branch 'mudcube/master' into dev