Tax system

- New tax system
- Advisor window modeled after SC3k's
- Advisor start_dialogue() function is now connected to a SimEvent "advisor_message" signal
- Advisor windows are now autoloaded and no longer part of the core interface node
- Added 3D buildings from Micropolis repo

scripts/windows.gd

@@ -0,0 +1,18 @@
+extends Control
+
+onready var debug_console = $Console
+onready var tax_window = $TaxWindow
+onready var advsior_meet_window = $AdvisorMeet
+
+func _ready():
+	SimEvents.emit_signal("city_planner", 0)
+
+func _process(delta):
+	if Input.is_action_pressed("ui_cheats"):
+		debug_console.show()
+
+func _on_TaxBtn_pressed():
+	tax_window.show()
+
+func _on_AdvsiorBtn_pressed():
+	advsior_meet_window.show()