direct i3 carriage collaborative wade remix

version of collaborative wade fused with i3 carriage.
i've found i3 carriage+adapter+collaborative wade having too many points of freedom. so fused i3 carriage with wade, skipping the adapter .

as side fx wade got rotated so (in theory) there should be a bit more room for second extruder.
this design is printable, but is not extensively tested yet.
it should be sturdier, and it has just three bolts to unscrew in case of carriage switch anyway so even less hassle to take it down th