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_append.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+import sys
+import mcrfpy
+print("1 - Creating scene")
+scene = mcrfpy.Scene("test")
+print("2 - Getting children")
+ui = scene.children
+print("3 - Creating frame")
+frame = mcrfpy.Frame(pos=(0,0), size=(50,50))
+print("4 - Appending frame")
+ui.append(frame)
+print("5 - Length check")
+print(f"len: {len(ui)}")
+print("DONE")
+sys.exit(0)