patch 7.4.1919

Problem:    Register contents is not merged when writing viminfo.
Solution:   Use timestamps for register contents.

src/vim.h

@@ -1075,9 +1075,11 @@ extern char *(*dyn_libintl_textdomain)(const char *domainname);
 /* The type numbers are fixed for backwards compatibility. */
 #define BARTYPE_VERSION 1
 #define BARTYPE_HISTORY 2
+#define BARTYPE_REGISTER 3
 
-#define VIMINFO_VERSION 2
+#define VIMINFO_VERSION 3
 #define VIMINFO_VERSION_WITH_HISTORY 2
+#define VIMINFO_VERSION_WITH_REGISTERS 3
 
 typedef enum {
     BVAL_NR,
@@ -1085,8 +1087,6 @@ typedef enum {
     BVAL_EMPTY
 } btype_T;
 
-#define BVAL_MAX 4	/* Maximum number of fields in a barline. */
-
 typedef struct {
     btype_T	bv_type;
     long	bv_nr;