MINOR: stats: replace the ST_* uri_auth flags with STAT_*

We used to rely on some config flags defined in uri_auth.h set during
parsing, and another set of STAT_* flags defined in stats.h set at run
time, with a somewhat gray area between the two sets. This is confusing
in the stats code as both are called "flags" in various functions and
it's quite hard to know which one describes what.

This patch cleans this up by replacing all ST_* by a newly assigned
value from the STAT_* set so that we can now use unified flags to
describe both the configuration and the current state. There is no
functional change at all.
diff --git a/include/common/uri_auth.h b/include/common/uri_auth.h
index 46f1bc6..8223dc1 100644
--- a/include/common/uri_auth.h
+++ b/include/common/uri_auth.h
@@ -26,13 +26,6 @@
 	char *px_id;			/* proxy id */
 };
 
-#define	ST_HIDEVER	0x00000001	/* do not report the version and reldate */
-#define	ST_SHNODE	0x00000002	/* show node name */
-#define	ST_SHDESC	0x00000004	/* show description */
-#define	ST_SHLGNDS	0x00000008	/* show legends */
-/* unused:              0x00000010 */
-#define	ST_SHOWADMIN	0x00000020	/* show the admin column */
-
 /* later we may link them to support multiple URI matching */
 struct uri_auth {
 	int uri_len;			/* the prefix length */
@@ -40,7 +33,7 @@
 	char *auth_realm;		/* the realm reported to the client */
 	char *node, *desc;		/* node name & description reported in this stats */
 	int refresh;			/* refresh interval for the browser (in seconds) */
-	int flags;			/* some flags describing the statistics page */
+	unsigned int flags;		/* STAT_* flags from stats.h and for applet.ctx.stats.flags */
 	struct stat_scope *scope;	/* linked list of authorized proxies */
 	struct userlist *userlist;	/* private userlist to emulate legacy "stats auth user:password" */
 	struct list http_req_rules;	/* stats http-request rules : allow/deny/auth */