Fix Features order on print Point > Line > Polygon

Fix #1639

KML for demo:

http://documents.epfl.ch/users/p/po/poncet/www/test/testing.kml

try print on <a href="http://mf-geoadmin3.dev.bgdi.ch/ltpoa/?X=154632.74&Y=552288.07&zoom=2&lang=fr&topic=ech&bgLayer=ch.swisstopo.pixelkarte-farbe&layers=KML%7C%7Chttp:%2F%2Fdocuments.epfl.ch%2Fusers%2Fp%2Fpo%2Fponcet%2Fwww%2Ftest%2Ftesting.kml"> corrected </a>

and on <a href="http://map.geo.admin.ch/?X=154632.74&Y=552288.07&zoom=2&lang=fr&topic=ech&bgLayer=ch.swisstopo.pixelkarte-farbe&layers=KML%7C%7Chttp:%2F%2Fdocuments.epfl.ch%2Fusers%2Fp%2Fpo%2Fponcet%2Fwww%2Ftest%2Ftesting.kml"> actual </a>

![evolving](https://cloud.githubusercontent.com/assets/8614223/5247337/b233b854-7971-11e4-857a-de886e8e1795.PNG)


indeed