lil optimization: less splitIntoParts in processInfillMesh (CURA-833)
lil optimization: less splitIntoParts in processInfillMesh (CURA-833)

Ultimaker/CuraEngine,alephobjects/CuraEngine,ROBO3D/CuraEngine,ROBO3D/CuraEngine,ROBO3D/CuraEngine,totalretribution/CuraEngine,totalretribution/CuraEngine,Ultimaker/CuraEngine,alephobjects/CuraEngine,alephobjects/CuraEngine,totalretribution/CuraEngine