Fix GPL-Compliance part 6 + Add Bumblebee model sources (Blender 2.79b) and SMD sources to compile using dpmodel

Completes one of the list from GPL-Compliance issue.

Bumblebee and its weapons sources matches to the xonotic-data.pk3dir compiled ones, the file size is exactly the same and works exactly same. Not need to create a new branch to optimize.

In Blender files, the UVs are fixed when the polys are converted to quads. Also, thanks to Triangulate modifier, the exported model polys are 'triangulated' to be ready.

Note: Bumblebee cockpit (where targets tag_viewport bone) uses spiderbot_cockpit.dpm