homogeneous 3d torus routing algorithm (XYZ, ZXYZ)

[yangyt96]

• The commits are 54f289f, 205249d, ea46140. The rest of the commits are same as the new pull request change of topology read location and netrace arbitrary NoC layout #95 because I want to test the 3d torus for netrace.
• This pull request requires this feature to work: jmjos/ratatoskr-tools@f74cc14 & 3d torus routing ratatoskr-tools#5 (comment)
• Tested on urand 4x4, 8x8x1, 8x8x2, 8x4x2, 4x4x4. All pass
• Tested on netrace 8x8x1, 8x8x2, 8x4x2, 4x4x4. All pass.

Q&A:

1. What is the goal?
   • The goal is to retrieve the xyz step value to compare the distances of 2 directions
2. Why not only xyz value is enough? (checkout this commit jmjos/ratatoskr-tools@3febaf5 line309-315)
   • To prevent the rounding different between c++ and python
3. Why add xyz-range? (jmjos/ratatoskr-tools@f74cc14)
   • to create a mapping from normalized coordinate to integer coordinate
     • map<Vec3D<float>,Vec3D<int>> norm_to_coord
     • The norm_to_coord is to know the z-position of the node (integer), then this value is required for the xy-step value of each layer
   • For future usage xyz-range value such as inhomogeneous NoC, it is recommended to add it in network.xml

I know it is not nice to increase the complexity of network.xml, but after I have considered it, I would suggest to add it in network.xml.