v0.24: Lots of small improvements

- Improved SVG export
- Allows to disable inputs and outputs in the measurement graph.
- Model analyzer is able to use switches as inputs.
- Editor is able to store views ([CRTL]+[[n]] to create, [[n]] to recall
  a view. So [CTRL]+[1] stores a view in slot one and [1] recalls it.
- The octal number format was added.
- A mirroring option was added to some components.
- Custom Java implemented components can now also implement HDL code to
  represent the component in an HDL export.
- Added a undo function to the table editor.
- Adds a command line interface for testing circuits.
- Allows to disable "snap to grid" in text and rectangle components.
- A push button combined with a LED was added.
- A VGA monitor was added.
- Improved naming of new Tunnels. Unnamed Tunnels are ignored silently.
- Overlapping pins are now connected.
- Added support for INOUT ports in HDL generation.
- Fixed an issue with Chinese text rendering.