download link on main page, refs #563

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15219 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
unfixing after 0.19.0, refs #563

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@15221 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
Merge branch 'master' into planet