Fail to export properly to svg and pdf with interactive paths

Export to SVG and PDF fails with [path_editor.py](http://matplotlib.org/examples/event_handling/path_editor.html) and similar programs, but it works fine with PNG. Indeed, the paths generated interactively are missing on the saved images.

It was tested on 1.2.1 and master.

**PNG** file:
![PNG file](http://i.stack.imgur.com/nW2Td.png)

**SVG** file:
![SVG file](http://i.stack.imgur.com/b82zJ.png)

I also opened a [question on Stack Overflow](http://stackoverflow.com/questions/16555845/failing-to-export-properly-to-svg-and-pdf-with-matplotlib).