Hinged Fan extension for "Printrbot Simple, 300mm Y Axis-No Sag!"

This is a hinged version of FablabMoebius' Fan extension for
iamjonlawrence's Y axis No Sag design.

I loved FablabMoebius' solution to keep the iamjonlawrence's
YFront piece from getting too hot and deforming, but found that
the fan was in the way if I needed to access the extruder to change
filament or to clear a jam, etc.

My solution was to make this a hinged part. It's a print in place
hinge so no worries about it coming apart during a print. I now
have the cooling I want without giving up easy access to the
extruder.

I also rounded a few of the corners, added a cable tie loop for wire
management, and got rid of the lip on the upright piece that made it
difficult to connect to the printer.

Printing details are on the instructions tab

Update: While this doesn't happen to the one I printed, someone
told me that theirs moves around while printing and asked for a way
to keep it in place, so I added a second file
(SwivelFanMountWithPegs.stl) which has two pegs you can use to
secure it with a small rubber band. I haven't printed this one yet,
but the changes are minor and I don't expect any problems with it.