TODO.txt

Business rules:
1. Not to add duplicate products to list
2. Add product quantity
3. Introduce product importance in the list
4. Implement list sorting according product importance
5. Permanently store created products list
   and load it on program startup
6. Add possibility to create different shopping lists
   Introduce shopping list title - must be unique
   across all user lists
7. Add possibility to manage shopping lists:
   implement CRUD for shopping lists
8. Introduce shopping list archive for deleted/used lists
9.

Next steps:
0. Single Responsibility Principle
1. Implement each menu step in separate class
2. Introduce Command design pattern
3. Introduce Strategy design pattern
4. Introduce three layer application architecture:
   UI, Business Logic, Data Access Layer

5. Database, SQL, JDBC API, DAL implementation
6. IoC, Business Logic implementation
7. HTML, CSS, simple Spring MVC introduction, UI implementation
8. ORM, Hibernate, JPA
9.