Anet A8 Motherboard box MKII - lid remix

Slight changes to the original great design - mostly to reduce filament usage to the box cover (lid):
* Changed ventilation holes to diamond shape so no support will be required when you choose Support Everywhere and added few more on the front panel
* Embedded 120-to-80 fan adjuster (reducer), again, to reduce filament consumption
* file "...lid 120fan mix v2.stl" has even bigger ventilation holes on the sides that should not require any support (I haven't printed this version, post a pictur