added visualization by loaded weight attribute refs #36

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16683 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
fix #948

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16684 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
normalizing randomTrip weights to [0,100] refs #948

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16685 29f149b2-0c63-11e1-8f5c-a347f6a9acd0