display the imaplib and python versions for each normal run

Some users might use more than one python/imaplib version. This tends to make
debugging and support harder.

Displaying this information by default for each run should help.

Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

offlineimap/init.py

@@ -1,5 +1,5 @@
 # OfflineIMAP initialization code
-# Copyright (C) 2002-2016 John Goerzen & contributors
+# Copyright (C) 2002-2017 John Goerzen & contributors
 #
 #    This program is free software; you can redistribute it and/or modify
 #    it under the terms of the GNU General Public License as published by
@@ -72,6 +72,11 @@ class OfflineImap(object):
       oi.run()
     """
 
+    def get_env_info(self):
+        return "imaplib2 v%s (%s), Python v%s"% (
+              imaplib.__version__, imaplib.DESC, PYTHON_VERSION
+        )
+
     def run(self):
         """Parse the commandline and invoke everything"""
         # next line also sets self.config and self.ui
@@ -180,9 +185,8 @@ class OfflineImap(object):
         glob.set_options(options)
 
         if options.version:
-            print("offlineimap v%s, imaplib2 v%s (%s), Python v%s"% (
-                  offlineimap.__version__, imaplib.__version__, imaplib.DESC,
-                  PYTHON_VERSION)
+            print("offlineimap v%s, %s"% (
+                offlineimap.__version__, self.get_env_info())
             )
             sys.exit(0)
 
@@ -273,6 +277,7 @@ class OfflineImap(object):
 
         # Welcome blurb.
         self.ui.init_banner()
+        self.ui.info(self.get_env_info())
 
         if options.debugtype:
             self.ui.logger.setLevel(logging.DEBUG)