DrBotIRC: fix an !alias add thinko with event handling ordering

before, !alias commands were handled via an on_pubmsg() in DrBotIRC,
which meant they happened (due to refactoring) after alias and
recursion scanning happened in a more low-level routine.

thus, if you were trying to add an alias that had recursion in it,
your alias would be the outcome of that recursion, not the command
to recurse. oops

DrBotIRC.py

@@ -99,14 +99,12 @@ class DrBotIRC(irclib.IRC):
         self.server = DrBotServerConnection(self)
         self.connections.append(self.server)
 
-        self.server.add_global_handler('pubmsg', self.on_pubmsg, 1)
-        self.server.add_global_handler('privmsg', self.on_pubmsg, 1)
-
         return self.server
 
     def _handle_event(self, connection, event):
         """Override event handler to do recursion."""
 
+        self.try_alias_cmds(connection, event)
         self.try_recursion(connection, event)
         self.try_alias(connection, event)
 
@@ -133,15 +131,24 @@ class DrBotIRC(irclib.IRC):
         if len(replies):
             event.arguments()[0] = '\n'.join(replies)
 
-    def on_pubmsg(self, connection, event):
-        """See if there is an alias ("!command") in the text, and if so, translate it into
-        an internal bot command and run it.
+    def try_alias_cmds(self, connection, event):
+        """See if there is an alias ("!command") in the text, and if so
+        do alias manipulation before any other recursion or aliasing.
         """
 
-        nick = irclib.nm_to_n(event.source())
-        userhost = irclib.nm_to_uh(event.source())
+        try:
+            nick = irclib.nm_to_n(event.source())
+        except (IndexError, AttributeError):
+            nick = ''
+        try:
+            userhost = irclib.nm_to_uh(event.source())
+        except (IndexError, AttributeError):
+            userhost = ''
         replypath = event.target()
-        what = event.arguments()[0]
+        try:
+            what = event.arguments()[0]
+        except (IndexError, AttributeError):
+            what = ''
         admin_unlocked = False
 
         # privmsg