SimplePositioner freaks out due multi-threading

[NuttyShrimp]

The class should be rewritten with some extra locks, or gather the info from the DB as the lappers do.
For some reason it will start freaking out with out of bound errors for the detections list, which is strange because it happens in the sorting function

[Topvennie]

Once Nostradamus is finished SimplePositioner can be removed. Unless we want to keep it as a simple (but bad) example of a positioner

[NuttyShrimp]

That will also be fixed if #135 is merged