Fix for: Add an OdometryWithAcceleration message

[m-naumann]

Fix acceleration message

Keep the name twist for velocities

Add documentation for treatment of incomplete information

[tfoote]

Sorry I edited my comments as I didn't realize that this was modifying the proposal not the core messages. But the semantic meaning and clarity comments still hold as well as the location of the covariance documentation.

[m-naumann]

No worries. I tried to make my point in the code comments, but it's probably a matter of taste whether to start improving the naming but therefore mixing old and new, or whether to only improve naming for entirely new messages.

About the covariance: If there is another convention/documentation anywhere, let me know. That was the only one I found, and I changed it to separate treatment of single entries as that's at least in the automated driving context very useful.

EDIT:

as well as the location of the covariance documentation.

I agree, that's probably worth a PR to update the documentation of the three messages itself. Maybe you can shortly tell me whether I should prepare a PR for those 3.