Initial reorg.

This is largely the same as #305, but updated for the current tree.

crates/misc/py/examples/import/env.py

@@ -0,0 +1,10 @@
+def callback(msg_p: 'i32', msg_len: 'i32') -> 'i32':
+    print('callback:', msg_p, msg_len)
+
+#    global memory
+#    mv = memoryview(memory)
+
+#    msg = bytes(mv[msg_p:(msg_p + msg_len)]).decode('utf-8')
+#    print(msg)
+
+    return 42