Filament Feeder Head Support (Creator/Replicator) Improved

I saw some problems with the originals, so here's my fix.
Changes:
• It's all one part. No assembly screws, and a nice big open space for accessing the single fixture screw.
• It fits the two types of dust filters on Thingiverse (the unit with two screws as well as the taller threaded version that I use).
• Vertical structure has added support ribs - even with 20% infill this seems to be more than stable enough, keeping the part lighter.
• Rear wire harness retainer is now intended to