Body-centred transform.
GetDegreesOfFreedom fries.
Reimplement rendering.
Debugging.
Cleanup.
Merge pull request #261 from pleroy/Transforms

A function to build a TransformingIterator for a body-centered frame.
After eggrobin's review.
Comments.
Merge pull request #262 from pleroy/Transforms

After eggrobin's review.
I cannot into numericz
also log positions and masses
Merge remote-tracking branch 'la-vache/master' into numerics-logging
Merge pull request #263 from eggrobin/silly-division

I cannot into numericz
Merge pull request #264 from eggrobin/numerics-logging

Numerics logging
Failing test.
New tests.
Test for failure, slow test is slow.
Sort of test something in Debug...
lint
typo yields strange bug.