[Routing] Derive data: number of lanes and capacity

[Mike N.]

> I would assume that all highway=* to be lanes=1
> (residential, secondary, service,...)
> except motorways with lanes=2
>
> Maybe highway=primary be 2 lanes too.

  There was a long discussion on a list about what to consider a 'lane' - 
center turn lanes, etc.    That's why I haven't tagged many lane attributes.
   I would have considered residential for example to have 2 lanes, but with 
2-way traffic.