Fixed Makefile's clean command and Renderer linking error.

Makefile

@@ -15,4 +15,4 @@ $(EXECUTABLE): $(OBJECTS)
 	$(CC) $(CFLAGS) $< -o $@
 
 clean:
-	rm -rf *o $(EXECUTABLE)
+	rm -rf src/*o $(EXECUTABLE)

src/Renderer.cpp

@@ -1,5 +1,7 @@
 #include "Renderer.h"
 
+std::vector<GuiComponent*> renderVector;
+
 void Renderer::registerComponent(GuiComponent* comp)
 {
 	renderVector.push_back(comp);

src/Renderer.h

@@ -13,8 +13,6 @@ namespace Renderer
 	void unregisterComponent(GuiComponent* comp);
 
 	void render();
-
-	std::vector<GuiComponent*> renderVector;
 }
 
 #endif