Support multi-person tracking

[trentwirth]

@philipqueen has a basic epipolar geometry setup working, testing functions here. Thinks we might not be doing intrinsics correctly - Philip is currently using the calibration .toml for now. @jonmatthis suggests testing with the equivalent of the identity matrix. Transformations are happening better when its closer to the center of the body... could be problems with distortion. Lots of testing/exploring

[trentwirth]

@philipqueen still in progress, needs data (two person recording) to start testing some of his math/code!

[trentwirth]

@philipqueen has done more testing ✔ , working towards next steps:

• adapt brightest point tracker (at least take a look at this)
• need two object/person recording;
  • get help from @MocapMike & the NEUMons!

[trentwirth]

@philipqueen has it working with two cameras and two objects, brightest point tracker!

Should be working with two cameras + any number of objects, but this needs to be tested. ❤

No linear thresholds;

The process works by optimal matching (might want to add thresholds later)