v0.23: Added generic circuits and simplified the integration of FPGA boards.

- Added generic circuits. Now it is possible to parameterize a sub circuit.
  Allows e.g. the creation of a barrel-shifter with selectable bit width.
- Circuit analyser is now able to analyse the built-in counters.
- Simplified the integration of FPGA boards.
  Board integration is now possible without creating Java code or
  even recompiling. See the BASYS3.config in examples/hdl as an example.
- Improved the label creation in the model analyzer.
- Improved performance of the boolean equation minimizer.
- Hex reader/writer supports RLE encoding like Logisim does.
- Added Spanish translation. Special thanks to Ángel Millán who provided
  the translation.
- Added a simple interactive beginners tutorial.
- Added a statistics dialog which shows the number of used components.
- Added scrollbars.
- Multiple break components are allowed.
- The fsm dialog loads the correct fsm if a circuit is open which
  is based on that fsm.
- If a VHDL defined component is used, ghdl now uses VHDL-2008.
- Added "Warren’s Crazy Small CPU" designed by Warren Toomey as a
  74xx circuit example.
- Fixed an issue in the "RAM, Chip select" component which was not fully
  asynchronous.
- Fixed swapped IC numbers 7447 and 7448.