Fix importing math to eval
Fix importing math to eval

We expose only math, so it can do mathematical operations on the setting values when translating.

Contributes to issue CURA-37.

senttech/Cura,hmflash/Cura,totalretribution/Cura,fieldOfView/Cura,senttech/Cura,totalretribution/Cura,Curahelper/Cura,ynotstartups/Wanhao,ynotstartups/Wanhao,fieldOfView/Cura,Curahelper/Cura,hmflash/Cura