Revert "cleanup semicolons, whitespace and mutable default arguments"

This reverts commit 7265682a4d.

sleekxmpp/basexmpp.py

@@ -25,6 +25,7 @@ from sleekxmpp.exceptions import IqError, IqTimeout
 from sleekxmpp.stanza import Message, Presence, Iq, StreamError
 from sleekxmpp.stanza.roster import Roster
 from sleekxmpp.stanza.nick import Nick
+from sleekxmpp.stanza.htmlim import HTMLIM
 
 from sleekxmpp.xmlstream import XMLStream, JID
 from sleekxmpp.xmlstream import ET, register_stanza_plugin
@@ -244,7 +245,7 @@ class BaseXMPP(XMLStream):
                 self.plugin[name].post_inited = True
         return XMLStream.process(self, *args, **kwargs)
 
-    def register_plugin(self, plugin, pconfig=None, module=None):
+    def register_plugin(self, plugin, pconfig={}, module=None):
         """Register and configure  a plugin for use in this stream.
 
         :param plugin: The name of the plugin class. Plugin names must