Add get_message_types() to plugin API

This allows plugins to specify the types of messages they handle. This
will be used specifically for the nickserv plugin, but could be useful
for other things too.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

omnibot/bot.py

@@ -61,7 +61,7 @@ class Bot:
         self.connection.register("JOIN", self.on_join)
         self.connection.register("PART", self.on_part)
         self.connection.register("KICK", self.on_kick)
-        self.connection.register("PRIVMSG", self.on_message)
+        self.connection.register("*", self.on_message)
         # Connect
         log.info("Connecting to %s", self.server_config.server)
         await self.connection.connect()
@@ -135,10 +135,16 @@ class Bot:
             # Don't raise on_message events for ourselves.
             return
         line = message.parameters[1]
-        plugins = self.channel_plugins(channel)
-        await asyncio.gather(
-            *[plugin.on_message(conn, channel, who, line) for plugin in plugins]
-        )
+        # Filter plugins by get_message_types() and channel
+        plugins = [
+            plugin
+            for plugin in self.channel_plugins(channel)
+            if message.command in plugin.get_message_types()
+        ]
+        if plugins:
+            await asyncio.gather(
+                *[plugin.on_message(conn, channel, who, line) for plugin in plugins]
+            )
 
     async def keepalive(self):
         # loop while we're connected, check every second