adding pass attr to connections, refs #2

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15515 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
refactoring xsds, refs #12

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15516 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
fixing plain.edg.xml attribute 'endOffset' (was written as 'offset')

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15517 29f149b2-0c63-11e1-8f5c-a347f6a9acd0