Create basic game entities

[fliepeltje]

A MapWindow should be the product of entities in a given time. For instance the player is an entity and based on the moves that a player makes, the player is rendered at different positions over time.

A simpler entity is a wall, which interacts with the player entity by stopping movement.

These entities have to have an iterative render, meaning that they have to have a certain position and action happening over time.

The core entities for making the simplest level are:

• Wall
• Player
• Level Exit