fixed:
- Plot figures not saved as SVG
  https://bugs.launchpad.net/latexdraw/+bug/1393692
- Rotating plot figures does not work properly
  https://bugs.launchpad.net/latexdraw/+bug/1393694
- Mirroring plot figures does not work properly
  https://bugs.launchpad.net/latexdraw/+bug/1393695
- Cannot change the roundness of the rectangles' corners
  https://bugs.launchpad.net/latexdraw/+bug/1395469
Release 3.3.1