Protoxtruder 2.0 Reinforced - remix for standard m3 bolt mounting

changed mounting to default m3 bolts from the top. added slits so the bolts can be moved into place. removed some material so the bolt heads have anough room. ** original design has been updated. front is now split into several parts so screws can be added without issues. So there's no need to use this remix unless you want to.