Fix map drawing issues

We were drawing way too many "lines" were the car didn't move at all. And we
occasionally drew incorrect lines from the last to the first location of a time
series.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Improve energy graph

- seperate y scales for speed and energy
- fix calculations for max energy / max regen
- draw speed with lower opacity to be able to see both speed and energy when
  displaying longer time series

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>