Included patch for persistent undo.  Lots of changes and added test.
diff --git a/src/os_mac.h b/src/os_mac.h
index 314ec32..f1ed965 100644
--- a/src/os_mac.h
+++ b/src/os_mac.h
@@ -204,7 +204,7 @@
 #endif
 
 #ifndef DFLT_VDIR
-#  define DFLT_VDIR	"$VIM/vimfiles/view"	/* default for 'viewdir' */
+# define DFLT_VDIR	"$VIM/vimfiles/view"	/* default for 'viewdir' */
 #endif
 
 #define DFLT_ERRORFILE		"errors.err"