optionally adding params in polyconvert shapefile import

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15608 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
adapting tests to new polyconvert option, refs #21

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15609 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
fix #1149

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15610 29f149b2-0c63-11e1-8f5c-a347f6a9acd0