2.1 Simplify3D GPX plugin

this is especially for Simplify3D program, it's the GPX plug-in, but opensourced, that allows fan pwm control, temperature control raised over the absurd gpx limit of 120 for HBP and 280 for extruders, and also some bugfixes emerged during the recreation of this plugin.

this is only windows binary, if you want to build under linux or mac, it should be relatively easy, if you encounter problems anyway, submit an issue or a pull request, so I can fix it.