[Tagging] Freeway exit tagging

[Georg Feddern]

I consider the visual lane assistance as it is named - as an assistance 
useful where there are several options.
If there is no assistance anybody who get the advice "take the exit" 
(*)  should obviously use the rightmost lane.
So even _no_ turn lane tagging would be an option for me in this (quite 
normal) case.

(*) Please do not cry "What about left-hand driving" - it is a 
right-hand example!
And any unusual left exit _should_ be tagged with lane assistance.