QuadTree.cs is now finished..

Added PossibleColliders().
Added Insert() part II.
Remove multiple functions from QuadTree.cs..

Removed GetAll()
Removed GetQuadrant()
Removed UpdateQuadrant()
Due to: Shouldn't use QuadTree for updates since components can be removed causing the collision check doing calculations on something that doesn't need any checking.
Added an overloaded Insert to QuadTree for lists.
Added a remove boolean to GDComp..

GameplayScreen will check after the collision check for components tagged for removal.

First implementation with QuadTree although not in the update-loop yet.
Removed the collision check in Screen.
Changed Insert() for lists in QuadTree to be compatible with GameComponentCollection.
Implemented and tested QuadTree