added warning for a dangerous condition (debug mode only) refs #2

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@14931 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
implementing #1051 (internal lanes with the same source and destination edge are now joined into a single internal edge). Full foward and backward compatibility since the network format does not change. Mostly netbuild/netwrite stuff. Minor adaption to lc-models to keep the old behavior now that internal edges may have multiple lanes

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@14932 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
patching expected results after [14932] refs #1051, #21

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@14933 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
fixing #1052 by modifying magic constant. see also #913

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@14934 29f149b2-0c63-11e1-8f5c-a347f6a9acd0