Implemented basic buying functions

- Renamed more scripts
- Switched license to Artistic 2.0

scripts/autoload/sim_data.gd

@@ -0,0 +1,32 @@
+extends Node
+
+var city_name: String
+var year: int = 1
+var prev_quarter: int
+var quarter: int = 1
+var population: int = 0
+var news_ticker: String
+
+var budget: int = 10000000
+var prev_budget: int
+
+var res_tax: int
+var comm_tax: int
+var indust_tax: int
+
+var fire_tax: int
+var police_tax: int
+var power_tax: int
+
+enum GameSpeed {SLOW, MEDIUM, FAST}
+
+func starting_budget(lev: int):
+	
+	if lev == 1 or lev == 0:
+		budget = 20000
+	elif lev == 2:
+		budget = 10000
+	elif lev == 3:
+		budget = 5000
+	else:
+		budget = NAN