Left handed duplicator 6 blower cooling duct with probe mount

Added 1bigpig's 12mm probe mount. It's offset 5mm more to the right, so make sure you are using the following lines in the firmware config instead of the ones provided:
` #define X_PROBE_OFFSET_FROM_EXTRUDER 40 // X offset: -left +right [of the nozzle]`
` #define Y_PROBE_OFFSET_FROM_EXTRUDER -16 // Y offset: -front +behind [the nozzle]`

I also improved printability. The nozzles are now connected to the main part from the first layer on so they don't come off during printing anymore. I also