Bug: crossing indices with edges are not realistic in every case

[dominicparga]

Example:
===>( )===>
===>( )===>
....... (+)===>
........ |

In the case above, we have 3 incoming and 3 leaving lanes. According to our parser, we set 1 crossroad (marked via brackets), because we have an edge from left with 2 lanes and an edge from bottom with 1 lane. Due to our crossing logic (using indices for every edge, not lane), vehicles from the left edge have to give priority to the bottom vehicle if right-before-left holds, but every vehicle could drive without intersection if lane mapping would be correct.

We can't fix this easily because we'd like to avoid storing vehicle's current lane info in a node (<=> crossroad).