re-implements the safebutton -> filename -> textfield
re-implements the safebutton -> filename -> textfield

Not yet fully functional but re-implemented for stringfreeze

Contributes to: issue CURA-125

Curahelper/Cura,senttech/Cura,markwal/Cura,senttech/Cura,Curahelper/Cura,totalretribution/Cura,fieldOfView/Cura,hmflash/Cura,ynotstartups/Wanhao,fxtentacle/Cura,totalretribution/Cura,fieldOfView/Cura,bq/Ultimaker-Cura,bq/Ultimaker-Cura,ad1217/Cura,ad1217/Cura,fxtentacle/Cura,markwal/Cura,hmflash/Cura,ynotstartups/Wanhao