Avoid use of printf()/fprintf()

Use one of the following functions where appropriate:

* puts() (whenever we print hard coded strings to stdout)
* fputs() (whenever we print hard coded strings to a stream)
* putchar() (whenever we print a single character to stdout)
* fputc() (whenever we print a single character to a stream)
* strncpy() (whenever we copy hard coded strings to a buffer)

This removes the overhead introduced by the format string parser and
reduces the number of false positive C-format strings spotted by
xgettext(1)'s heuristics.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/keys.c

@@ -444,7 +444,7 @@ keys_format_label (char *key, int keylen)
 
   bzero (fmtkey, sizeof (fmtkey));
   if (len == 0)
-    (void)snprintf (fmtkey, sizeof (fmtkey), "?");
+    (void)strncpy (fmtkey, "?", sizeof (fmtkey));
   else if (len <= keylen)
     {
       for (i = 0; i < keylen - len; i++)