ZOrbiter 1.5 fan mod

I really liked the ZOrbiter extruder, however the cooling was a bit lacking. So I remixed the extruder cover to work with the RHD and Delta P fan mods. Both had to be altered a bit. 

Also, I added heat inserts to the extruder cover and extruder body to make assembly easier.

Both fan shrouds have been validated on my Bear and work great. Overall, the Delta P seems to work a bit better.

Print according to ZOrbiter instructions. The fan shrouds need to be printed in ABS or ASA.