Changes:
1. Det can now display the created keys in the form of tree view. This helps to understand, was the system builed correctly. Also, it is possible to look at the corresponding question selecting the tree item.
2. It is possible to look at the internal structure of any rule in the system.
3. Specialised editor with syntax highlighting added to edit the keys being created.
4. It is possible to go to any final conclusion selecting the corresponding name in the "preliminary conclusions" window.
5. Also many minor changes: now allows to change font, remembers window position, can change the database file without restart and so on.