tests for the last few issues (these test scripts should work with recent APIs, while the rest of the test suite needs an overhaul)

tests/test_iter_flush.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+import sys
+import mcrfpy
+print("1 - Creating scene", flush=True)
+scene = mcrfpy.Scene("test")
+print("2 - Getting children", flush=True)
+ui = scene.children
+print("3 - Creating frame", flush=True)
+frame = mcrfpy.Frame(pos=(0,0), size=(50,50))
+print("4 - Appending frame", flush=True)
+ui.append(frame)
+print("5 - Starting iteration", flush=True)
+for item in ui:
+    print(f"Item: {item}", flush=True)
+print("6 - Iteration done", flush=True)
+sys.exit(0)