Version 0.6.6

Changelog for version 0.6.6:

• Fixed a typo in the tooltip for the Demux component.
  
• Fixed an issue with "prev" lines in histograms being drawn when the result falls outside the interval.
  
• Added a check to prevent blueprints containing source or I/O components.
  
• Added new test cases and updated existing ones for levels 30 and 40 to prevent solutions that only work for specific inputs.
  
• Updated the option for automatically creating a new solution for levels without solutions (accessible via the Next Level and Previous Level buttons in the Histograms menu) to also apply when loading a level from the "Levels" menu.