added lane coloring by angle refs #36 (to figure out directions without connection arrows)

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16315 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
fixing #1252

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16316 29f149b2-0c63-11e1-8f5c-a347f6a9acd0