patch 7.4.1911

Problem:    Recent history lines may be lost when exiting Vim.
Solution:   Merge history using the timestamp.

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1911,
 /**/
     1910,
 /**/