various small improvements.

lua_func validation in progress.

test/validation/items/lua_func/lua_func.lua

@@ -0,0 +1,30 @@
+tm = require("tm")
+
+local module = {}
+
+function module.donothing(param)
+    return 0
+end
+
+function module.assertparam(param)
+    assert(param)
+end
+
+function module.checkglobal(param, index)
+    return tm.gd("lua_data_to_be_returned")[index]
+end
+
+function module.should_not_be_called(param)
+    assert(false)
+end
+
+function module.echo(param)
+    return param
+end
+
+function module.tuple_return(first, second)
+    return first, second
+end
+
+
+return module