Undo last change: a path is not unpaved by default

See http://wiki.openstreetmap.org/wiki/Tag:highway%3Dpath
path="A route open to the public which is not intended for motor vehicles"
"These routes may have any type of surface."

See also http://wiki.openstreetmap.org/wiki/Highway_examples
Merge pull request #136 from GiZig/patch-11

Undo last change: a path is not unpaved by default