Update restriction relations when a way is split in LinkDestinationHook

When using --process-destination and --process-exits the links are split into multiple parts. The restrictions need to be updated with the new id of the split way if the split part is relevant for the restriction. 

git-svn-id: http://svn.mkgmap.org.uk/mkgmap/trunk@2995 25d90789-57f7-4ee0-8453-03a3dfeeeb22