Add a censored strings list feature.

Censored strings are defined by a censored_strings array in the config
file. An offending string will be replaced with [censored] in the bot's
output.

core/config.py

@@ -8,7 +8,7 @@ def save(conf):
 
 if not os.path.exists('config'):
     open('config', 'w').write(inspect.cleandoc(
-        '''
+        r'''
         {
           "connections":
           {
@@ -21,7 +21,19 @@ if not os.path.exists('config'):
           },
           "disabled_plugins": [],
           "disabled_commands": [],
-          "acls": {}
+          "acls": {},
+          "censored_strings":
+          [
+            "DCC SEND",
+            "1nj3ct",
+            "thewrestlinggame",
+            "startkeylogger",
+            "hybux",
+            "\\0",
+            "\\x01",
+            "!coz",
+            "!tell /x"
+          ]
         }''') + '\n')
 
 

core/irc.py

@@ -16,6 +16,15 @@ def decode(txt):
     return txt.decode('utf-8', 'ignore')
 
 
+def censor(text):
+    replacement = '[censored]'
+    if 'censored_strings' in bot.config:
+        words = map(re.escape, bot.config['censored_strings'])
+        regex = re.compile('(%s)' % "|".join(words))
+        text = regex.sub(replacement, text)
+    return text
+
+
 class crlf_tcp(object):
     "Handles tcp connections that consist of utf-8 lines ending with crlf"
 
@@ -181,7 +190,7 @@ class IRC(object):
     def cmd(self, command, params=None):
         if params:
             params[-1] = ':' + params[-1]
-            self.send(command + ' ' + ' '.join(params))
+            self.send(command + ' ' + ' '.join(map(censor, params)))
         else:
             self.send(command)