Integrate singleton pattern into Core, Controller, Renderer and World classes
Integrate basic state based structure
Fix menu render problem
Adapt to MVC concept
Delete terrible controller instance creation
Refactoring
Merge pull request #4 from alexanderguk/feature/state-based-game

Feature: state based game
Fixing enum problem and mistakes in MVC
Merge remote-tracking branch 'origin/develop' into develop

Conflicts:
	src/core/controller/gameplay/HeroController.java
Merge results
Create correct state resource managing
Menu bug fix
Refactoring, VSync replacing
Updated Model-View interactions
Refactoring
Fixing View
Refactoring
All the Model changes replaced to the Controller
Fix start menu enter process; add pause menu
Fix problem with the same part of code in each inheriors of GameObjectRenderer in method render(...).