Rename safe_strncpy() to strlcpy().

This cleans up the use of safe_strncpy() even more.  Since it has the
same semantics as strlcpy() use this name instead.  Also move the
definition from inside path.c to its own file compat/strlcpy.c, and use
it conditionally at compile time, since some platforms already has
strlcpy().  It's included in the same way as compat/setenv.c.

Signed-off-by: Peter Eriksen <s022018@student.dtu.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>

path.c

@@ -77,25 +77,12 @@ int git_mkstemp(char *path, size_t len, const char *template)
 		pch += n;
 	}
 
-	safe_strncpy(pch, template, len);
+	strlcpy(pch, template, len);
 
 	return mkstemp(path);
 }
 
 
-size_t safe_strncpy(char *dest, const char *src, size_t size)
-{
-	size_t ret = strlen(src);
-
-	if (size) {
-		size_t len = (ret >= size) ? size - 1 : ret;
-		memcpy(dest, src, len);
-		dest[len] = '\0';
-	}
-	return ret;
-}
-
-
 int validate_symref(const char *path)
 {
 	struct stat st;