Add index argument to constructor of MathObject
Add index argument to constructor of MathObject

folderIdx is the index of the folder the new object should be added
to in mathTree. It defaults to the last folder.

stardust66/math3d,stardust66/math3d,ChristopherChudzicki/math3d,ChristopherChudzicki/math3d,ChristopherChudzicki/math3d,ChristopherChudzicki/math3d,stardust66/math3d,stardust66/math3d