Fixed structure diagram display on umpleonline.
The out of sync warning now always appears at the top of the canvas.
Warning and error messages work for structure diagrams.
Structure diagrams no longer disappear when there is an error.



git-svn-id: http://umple.googlecode.com/svn/trunk@4237 6ebf9d09-8eb1-0036-9d08-68c07d1b990a