CHANGED:
tried some things in context with assertions
ADDED:
a lot of implementations
ADDED:
Imlementations and tests for EdgeRings
TODO:
Fix this:
../Subdiv3/TestManifold.cpp:148: Failure
Value of: 3
Expected: ring->computeEdgeRingSize()
Which is: 1
[  FAILED  ] Manifold.EdgeRingLinking (0 ms)
[----------] 5 tests from Manifold (0 ms total)