Fix DeprecationWarning with system-wide argparse.

IPython/config/loader.py

@@ -325,6 +325,7 b' class ArgParseConfigLoader(CommandLineConfigLoader):'
             argv = sys.argv[1:]
         self.argv = argv
         self.parser_args = parser_args
+        self.version = parser_kw.pop("version", None)
         kwargs = dict(argument_default=argparse.SUPPRESS)
         kwargs.update(parser_kw)
         self.parser_kw = kwargs

IPython/core/application.py

@@ -70,9 +70,15 b' class BaseAppConfigLoader(ArgParseConfigLoader):'
             help='Set the log level (0,10,20,30,40,50).  Default is 30.',
             metavar='Global.log_level')
 
+    def _add_version(self, parser):
+        """Add the --version option to the parser."""
+        parser.add_argument('--version', action="version",
+                                                version=self.version)
+
     def _add_arguments(self):
         self._add_ipython_dir(self.parser)
         self._add_log_level(self.parser)
+        self._add_version(self.parser)
 
 
 class Application(object):