sprintf to snprintf conversion

Move out string operations to another file, and introduce a frontend
to snprintf for various situations.  This change is important for
catching and eliminating sprintf overflows, which are as of now many
times silently corrupting memory.

Signed-off-by: Dan Farina <drfarina@acm.org>
Signed-off-by: Peter van Hardenberg <pvh@heroku.com>

config.c

@@ -1,12 +1,16 @@
 /*
  * config.c
+ *
  * Copyright (c) 2ndQuadrant, 2010
+ * Copyright (c) Heroku, 2010
  *
  * Functions to parse the config file
  */
 
 #include "repmgr.h"
 
+#include "strutil.h"
+
 void
 parse_config(const char *config_file, char *cluster_name, int *node,
 			 char *conninfo)