[Tagging] access in the wiki: move psv to "by use"

[martinq]

Hi,

sorry, made a mistake:

> 2) If other restrictions (maxweight or - more precisely - maxgcweight,
> maxgcweightrating or maxactualweight) are made conditional, we need an
> update of our conditional tagging, for example by introducing "use":

Of course this is already possible in conditional restrictions without 
"use=":

So the given example can already be expressed with the existing 
conditional restrictions:

A maximum weight rating of 7.5 for everyone except public transport bus
or agricultural traffic
maxgcweightrating=7.5
maxgcweightrating=none @ agricultural
maxgcweightrating:bus=none @ public_transport

There is no issue #2, no modification needed, the "use"-values already work.

martinq