improved junctions.join heuristic (better recognition of geometry-like node leads to smaller clusters)

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15629 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
improved junctions.join heuristic (avoiding parallel outgoing edges, similar to [15623])

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15630 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
some fixes to protobuf encoding, refs #1138

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15631 29f149b2-0c63-11e1-8f5c-a347f6a9acd0