patching comments refs #2

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15339 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
now returning correct z-coordinate when converting road position to 3DPosition or LonLatAltPosition. extended python traci library by method convert3D to request this conversion

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15340 29f149b2-0c63-11e1-8f5c-a347f6a9acd0