Fix Eagle footprint library import of arcs. (fixes lp:1399745)

        wxPoint end(   kicad_x( w.x2 ), kicad_y( w.y2 ) );

        int     width = kicad( w.width );

        EDGE_MODULE* dwg = new EDGE_MODULE( aModule, S_SEGMENT );

        aModule->GraphicalItems().PushBack( dwg );

        EDGE_MODULE* dwg;

        if( !w.curve )

        {

            dwg = new EDGE_MODULE( aModule, S_SEGMENT );

            dwg->SetStart0( start );

            dwg->SetEnd0( end );

        }

        else

        {

            dwg = new EDGE_MODULE( aModule, S_ARC );

            // Eagle give us start and end.

            // S_ARC wants start to give the centre, and end to give the start

            double dx = end.x - start.x, dy = end.y - start.y;

            wxPoint mid = (start + end) / 2;

            double dlen = sqrt( dx*dx + dy*dy );

            double dist = dlen / ( 2 * tan( DEG2RAD( *w.curve ) / 2 ) );

            wxPoint centre(

                mid.x + dist * ( dy / dlen ),

                mid.y - dist * ( dx / dlen )

            );

            dwg->SetStart0( centre );

            dwg->SetEnd0( start );

            dwg->SetAngle( *w.curve * -10.0 ); // KiCad rotates the other way

        }

        dwg->SetLayer( layer );

        dwg->SetWidth( width );

        aModule->GraphicalItems().PushBack( dwg );

    }

}