Fixed Force Arrrow Visualization/ Proc3D Overhaul

[jgoppert]

This required a significant overhaul of the proc3d library, but it is working now as far as I can tell. I didn't attempt to fix the blender backend for the updates to the proc3d library, but it shouldn't take much work hopefully with the simplifications to proc3d that I made.

[jgoppert]

I just took the time to get this working with master again. I think it is worth looking at. Not having force arrows etc. is a real problem and this fixes that. I still haven't updated the blender backend, but can anyone actually get the blender backend working? I would update the blender backend if I could get it working.

[jgoppert]

Note this includes the cmake-fix pull request so I could test it out easily.

[sjoelund]

This also has the USE_OMC=1 default :(

[jgoppert]

Removed it.

[sjoelund]

This pull request doesn't work as expected. At least for DoublePendulum (the pendulum is connected).

Also, how do I test force arrows?

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