improve tools for protocol handling

generate.py

@@ -59,6 +59,9 @@ class Top:
         else:
             raise ValueError("One of title or message is needed")
 
+        if self.body is None:
+            self.body = ""
+
     def __repr__(self):
         return "<TOP "+self.title+">"
 
@@ -92,12 +95,18 @@ def weekday(indate):
     return WEEKDAYS[indate.weekday()]
 
 def prototop(top):
+    result  = ""
+
     if "protostub" in dir(top) and top.protostub:
-        return j2env.from_string(top.protostub).render(context, top=top)
+        result = j2env.from_string(top.protostub).render(context, top=top)
     elif top.body:
-        return j2env.from_string(top.body).render(context)
-    else:
-        return None
+        result = j2env.from_string(top.body).render(context)
+
+    for search,replace in config["protoreplace"].items():
+        result = result.replace(search, replace)
+
+    return result
+
 
 def conf2top(top):
     sender = None