make the trash and spam folder names in Gmail accounts configurable

offlineimap.conf

@@ -436,3 +436,13 @@ remoteuser = username@gmail.com
 #
 # See http://mail.google.com/support/bin/answer.py?answer=77657&topic=12815
 realdelete = no
+
+# The trash folder name may be different from [Gmail]/Trash
+# for example on german googlemail, this setting should be
+#
+# trashfolder = [Google Mail]/Papierkorb
+#
+# The same is valid for the spam folder
+#
+# spamfolder = [Google Mail]/Spam
+