patch 8.2.0514: several global functions are used in only one file

Problem:    Several global functions are used in only one file.
Solution:   Make the functions static. (Yegappan Lakshmanan, closes #5884)

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    514,
 /**/
     513,
 /**/
@@ -2234,6 +2236,7 @@ list_version(void)
 }
 
 static void do_intro_line(int row, char_u *mesg, int add_version, int attr);
+static void intro_message(int colon);
 
 /*
  * Show the intro message when not editing a file.
@@ -2253,7 +2256,7 @@ maybe_intro_message(void)
  * Only used when starting Vim on an empty file, without a file name.
  * Or with the ":intro" command (for Sven :-).
  */
-    void
+    static void
 intro_message(
     int		colon)		// TRUE for ":intro"
 {