* KSEntity.cs: * Refactored to use a generic dictionary instead of
  subclassing generic list to increase performance.
* Added generic methods for more convenient access.
* Added RemoveComponent() method.

* KSEntityManager.cs: Refactored to subclass HashSet<T> instead of
  List<T> for better performance.

* TestEntity.cs:
* TestSystem.cs:
* TestEntitiy.csproj:
* TestEntityManager.cs:
* IntEntity.cs:
* HealthSystem.cs:
* IntEntityManager.cs: