refactoring flow insertion, refs #1347

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16736 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
adapting to new flow insertion, refs #21

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16737 29f149b2-0c63-11e1-8f5c-a347f6a9acd0