Fix a few simple typos (#1476)

Closes #1475

src/callbacks.py

@@ -1145,7 +1145,7 @@ class NestedCommandsIrcProxy(ReplyIrcProxy):
         # evaluated our own list of arguments.
         assert not self.finalEvaled, 'finalEval called twice.'
         self.finalEvaled = True
-        # Now, the way we call a command is we iterate over the loaded pluings,
+        # Now, the way we call a command is we iterate over the loaded plugins,
         # asking each one if the list of args we have interests it.  The
         # way we do that is by calling getCommand on the plugin.
         # The plugin will return a list of args which it considers to be

src/drivers/__init__.py

@@ -61,7 +61,7 @@ class IrcDriver(object):
         raise NotImplementedError
 
     def die(self):
-        # The end of any overrided die method should be
+        # The end of any overridden die method should be
         # "super(Class, self).die()", in order to make
         # sure this (and anything else later added) is done.
         remove(self.name())

src/registry.py

@@ -445,7 +445,7 @@ class Value(Group):
             # The complicated case. We want a net+chan specific value,
             # which may come in three different ways:
             #
-            # 1. it was set explicitely net+chan
+            # 1. it was set explicitly net+chan
             # 2. it's inherited from a net specific value (which may itself be
             #    inherited from the base value)
             # 3. it's inherited from the chan specific value (which is not a
@@ -453,7 +453,7 @@ class Value(Group):
             #    load configuration from old bots).
             #
             # The choice between 2 and 3 is done by checking which of the
-            # net-specific and chan-specific values was set explicitely by
+            # net-specific and chan-specific values was set explicitly by
             # a user/admin. In case both were, the net-specific value is used
             # (there is no particular reason for this, I just think it makes
             # more sense).