Changed Float32Attribute to BufferAttribute

 Float32Attribute is deprecated
Changed position copying from = to copy()

spStart.position = I.point; -> spStart.position.copy(I.point);
spEnd.position = I.point; -> spEnd.position.copy(I.point);
merged changes from marteenvm
updated to three.js r68
updated point_picking example to three.js r68
Merge remote-tracking branch 'origin/develop'