Go to previous path / restart path

[11phc]

Added actions for go to previous path, restart existing path, and go to previous path index segment (which I'm not sure how useful it will be, but it's there now anyway).

These are useful for manually telling the mower to repeat bits it has gotten stuck on or done badly and so on.

[rovo89]

Sorry for hijacking this PR, but since you got yourself familiar with the skip back/ahead topic, I was wondering what you think about the following. I'm working on building a "playlist" feature, where a separate node manages the list of areas to mow right now, along with some settings, and instructs mower_logic to mow certain paths. My thought is that controls like the ones you implemented and proposed would be handled by the new node. Especially jumping back wouldn't be possible for mower_logic to handle as it will only knows the calculated paths for the current area.

For the implementation, I was thinking about sending an "abort" command first if any of the actions are triggered and then sending a new command with the adjusted area/path/index. Do you see any issues with that?

[11phc]

Hi Robert, I am perhaps not the right person to ask as my knowledge is not that in depth on the overall workings of the logic. A new node with a playlist feature sounds a good idea and might ultimately be able to supersede the current sequential functionality, which is not ideal at all for multiple and complicated areas. My actions I have implemented here could run alongside yours and then perhaps ultimately be deprecated once your system is up and running smoothly?