add motd schema and motd editor

app/lib/babycode.py

@@ -218,10 +218,14 @@ def should_collapse(text, surrounding):
 
     return False
 
-def babycode_to_html(s):
+def babycode_to_html(s, banned_tags=None):
+    allowed_tags = list(TAGS.keys())
+    if banned_tags is not None:
+        for tag in banned_tags:
+            allowed_tags.remove(tag)
     subj = escape(s.strip().replace('\r\n', '\n').replace('\r', '\n'))
     parser = Parser(subj)
-    parser.valid_bbcode_tags = TAGS.keys()
+    parser.valid_bbcode_tags = allowed_tags
     parser.bbcode_tags_only_text_children = TEXT_ONLY
     parser.valid_emotes = EMOJI.keys()