Version 0.0.0.007

What's new:
1. Created parent class AbstractModel in which all general methods will be implemented.
2. Was change the way of calling event. Now Listener uses a constant identificator in the Button class
3. Created parent model class for each object in the game - snake cell, snake head, food, wall cell and so on.
4. Created empty classes for the models
5. Changed id for each members. End is always will be 0;
6. Buttons now can be active or unactive. Drawing is empty right now.
7. First steps for the new_game processor. Now programm process pressing NEW_GAME button correctly

TO DO LIST:
 - File parser for loader
 - NEW_GAME button processor
 - Draw to unactive buttons