various small improvements.

lua_func validation in progress.

test/validation/items/py_func/py_func.py

@@ -0,0 +1,26 @@
+import py_func.tm as tm
+
+class ValidationTest(tm.FunctionItem):
+    def exec(self, param):
+        print(str(param))
+        return 0
+
+def donothing():
+    return 0
+
+def assertparam(param):
+    assert param
+    return 0
+
+def checkglobal(param):
+    assert param=='test parameter'
+    return 0
+
+def should_not_be_called(param):
+    raise
+
+def echo(param):
+    return param
+
+def tuple_return(first, second):
+    return first, second