fix odometry issue in diff_drive_controller

[roncapat]

Fixes #286 and the issue introduced in #260.

[roncapat]

Some considerations:
updateFromVelocity() takes as input not velocities, but position deltas...
Lots of solutions here to transform a bit the Odometry API, but my idea is:

• rename updateFromVelocity() to updateFromPositionDeltas()
• rename update() to updateFromPosition()
• then, add a proxy method updateFromVelocity() that keeps the same parameters and internally computes dt to avoid to explicitly multiply by update_dt.seconds() as this patch currently does

Or:

• change the set of parameters for the different Odometry methods, as proposed in [DiffDriveController] use "period" argument in the update method insead of calculating "dt" #271.
• I believe that doing this will make the Odometry class less robust though. For now, it is something that integrates feedback readings at specified (through parameter time) timepoints. Passing instead time deltas would remove some nice semantic... No way to check if for example the passed timepoint follows or precedes the previously provided timepoint. and of course, modifying the API to pass both (time and time delta) would be redundant.

[destogl]

Just a minor comment.

Nevertheless, we should rename the method now, or, why not to change it accepts additionally dt?

Should this then make all other steps unnecessary, or am I missing something?

[roncapat]

I would go with the renaming scheme I proposed if it's ok for you.

[destogl]

I would go with the renaming scheme I proposed if it's ok for you.

We can do this if it is really needed. I would have to review the whole controller again to see the consequences.

[bmagyar]

This is already solving a problem which we need fixed. I'll go ahead with merging and @roncapat please submit a second PR with the renaming suggestions.