Update runtime files. Add support for J.
diff --git a/runtime/doc/undo.txt b/runtime/doc/undo.txt
index 2589a15..414a63b 100644
--- a/runtime/doc/undo.txt
+++ b/runtime/doc/undo.txt
@@ -1,4 +1,4 @@
-*undo.txt* For Vim version 7.4. Last change: 2013 Aug 22
+*undo.txt* For Vim version 7.4. Last change: 2013 Sep 08
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -249,8 +249,9 @@
detect if an undo file is no longer synchronized with the file it was written
for (with a hash of the file contents) and ignore it when the file was changed
after the undo file was written, to prevent corruption. An undo file is also
-ignored if its owner differs from the owner of the edited file. Set 'verbose'
-to get a message about that when opening a file.
+ignored if its owner differs from the owner of the edited file, except when
+the owner of the undo file is the current user. Set 'verbose' to get a
+message about that when opening a file.
Undo files are normally saved in the same directory as the file. This can be
changed with the 'undodir' option.