* a pstoedit bug in Ubuntu 'lucid' causes a non-zero return code for the eps->dxf conversion
* this exit code (-11) is accepted with a warning now


git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@740 bbaffbd6-741e-11dd-a85d-61de82d9cad9