Migrate nodes

- XyzAdd
- XyzSubtract
- XyzNegate
- XyzScaleOffset
- PointNormalDistance
- FacesByLine
- StructuralFraming

Also fixed the position of new nodes generated during one-to-many migrations:
![image](https://cloud.githubusercontent.com/assets/6386550/2665036/4afa8760-c087-11e3-9f30-2136eb1a3180.png)