Add initialization parameters for Brush class and Add check validation

[G2Pavon]

Change the initialization from Brush.__init__(self) to Brush.__init__(self, faces).

Check if the given faces create a valid brush:

• len(faces) >= 4
• not infinitely large
• not empty

[G2Pavon]

Initialization parameter was added, but they are not required. Added brush valid verification if len(faces) >= 4. 1b091cb

TODO:

• make parameter required (Requirements: Refactor load_map())
• check if brush is infinetely large