Update documentation files.
diff --git a/runtime/doc/undo.txt b/runtime/doc/undo.txt
index c50e639..0659948 100644
--- a/runtime/doc/undo.txt
+++ b/runtime/doc/undo.txt
@@ -1,4 +1,4 @@
-*undo.txt* For Vim version 7.2. Last change: 2006 Apr 30
+*undo.txt* For Vim version 7.2. Last change: 2009 Apr 12
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -106,6 +106,10 @@
After this an "u" command will undo the delete command and the previous
change.
+To do the opposite, break a change into two undo blocks, in Insert mode use
+CTRL-G u. This is useful if you want an insert command to be undoable in
+parts. E.g., for each sentence. |i_CTRL-G_u|
+
==============================================================================
4. Undo branches *undo-branches* *undo-tree*