- don't ignore no_entry restriction relation if it has 
multiple 'from' ways and one way is not routable or outside bbox,
as long as one routable 'from' way remains
- don't ignore no_exit restriction relation if it has 
multiple 'to' ways and one way is not routable or outside bbox
as long as one routable 'to' way remains

git-svn-id: http://svn.mkgmap.org.uk/mkgmap/trunk@3182 25d90789-57f7-4ee0-8453-03a3dfeeeb22