#3586
Corner[pic1, 2] now follow the picture when view is zoomed
(TODO : optimize it so that the algo doesn't update if the image has at least two points to locate it)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27990 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e