fixing node retrieval by position

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15429 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
preparing failing test for rerouting on internal lanes

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15430 29f149b2-0c63-11e1-8f5c-a347f6a9acd0