[MINOR] switch all stat counters to 64-bit

The byte counters have long been 64-bit to avoid overflows. But with
several sites nowadays, we see session counters wrap around every 10-days
or so. So it was the moment to switch counters to 64-bit, including
error and warning counters which can theorically rise as fast as session
counters even if in practice there is very low risk.

The performance impact should not be noticeable since those counters are
only updated once per session. The stats output have been carefully checked
for proper types on both 32- and 64-bit platforms.
diff --git a/include/types/server.h b/include/types/server.h
index 8fb8a1f..a52a9d8 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -116,16 +116,16 @@
 	struct eb_root *lb_tree;                /* we want to know in what tree the server is */
 	struct server *next_full;               /* next server in the temporary full list */
 
-	unsigned failed_checks, down_trans;	/* failed checks and up-down transitions */
+	long long failed_checks, down_trans;	/* failed checks and up-down transitions */
 	unsigned down_time;			/* total time the server was down */
 	time_t last_change;			/* last time, when the state was changed */
 
-	unsigned failed_conns, failed_resp;	/* failed connect() and responses */
-	unsigned retries, redispatches;		/* retried and redispatched connections */
-	unsigned failed_secu;			/* blocked responses because of security concerns */
+	long long failed_conns, failed_resp;	/* failed connect() and responses */
+	long long retries, redispatches;		/* retried and redispatched connections */
+	long long failed_secu;			/* blocked responses because of security concerns */
 	struct freq_ctr sess_per_sec;		/* sessions per second on this server */
-	unsigned cum_sess;			/* cumulated number of sessions really sent to this server */
-	unsigned cum_lbconn;			/* cumulated number of sessions directed by load balancing */
+	long long cum_sess;			/* cumulated number of sessions really sent to this server */
+	long long cum_lbconn;			/* cumulated number of sessions directed by load balancing */
 
 	long long bytes_in;			/* number of bytes transferred from the client to the server */
 	long long bytes_out;			/* number of bytes transferred from the server to the client */