Added State Manager

Udah bingung jadinya ambil dari
https://github.com/eXpl0it3r/SmallGameEngine
press escape to back to menu title, filled playstate from master
use template for method function
SFML configuration
used pragma once
added graph file for Szirmay-Kalos algorithm
make it compileable
able to draw city
fix definition succession
more clean up for cities
fix bug
added shortest route for all city
refactored input and others