[MINOR] store HTTP error messages into a chunk array

HTTP error messages were all specific cases handled by an IF.
Now they are all in an array so that it will be easier to add
new ones. Also, the return functions now use chunks as inputs
so that it should be easier to provide alternative return
messages if needed.
diff --git a/include/types/httperr.h b/include/types/httperr.h
index c594048..c466328 100644
--- a/include/types/httperr.h
+++ b/include/types/httperr.h
@@ -32,6 +32,19 @@
 #define DATA_ST_INIT	0
 #define DATA_ST_DATA	1
 
+/*
+ * All implemented return codes
+ */
+enum {
+	HTTP_ERR_400 = 0,
+	HTTP_ERR_403,
+	HTTP_ERR_408,
+	HTTP_ERR_500,
+	HTTP_ERR_502,
+	HTTP_ERR_503,
+	HTTP_ERR_504,
+	HTTP_ERR_SIZE
+};
 
 
 #endif /* _TYPES_HTTPERR_H */
diff --git a/include/types/proxy.h b/include/types/proxy.h
index a82f195..8480143 100644
--- a/include/types/proxy.h
+++ b/include/types/proxy.h
@@ -34,6 +34,7 @@
 #include <common/regex.h>
 
 #include <types/buffers.h>
+#include <types/httperr.h>
 #include <types/session.h>
 #include <types/server.h>
 
@@ -125,22 +126,7 @@
 	int grace;				/* grace time after stop request */
 	char *check_req;			/* HTTP or SSL request to use for PR_O_HTTP_CHK|PR_O_SSL3_CHK */
 	int check_len;				/* Length of the HTTP or SSL3 request */
-	struct {
-		char *msg400;			/* message for error 400 */
-		int len400;			/* message length for error 400 */
-		char *msg403;			/* message for error 403 */
-		int len403;			/* message length for error 403 */
-		char *msg408;			/* message for error 408 */
-		int len408;			/* message length for error 408 */
-		char *msg500;			/* message for error 500 */
-		int len500;			/* message length for error 500 */
-		char *msg502;			/* message for error 502 */
-		int len502;			/* message length for error 502 */
-		char *msg503;			/* message for error 503 */
-		int len503;			/* message length for error 503 */
-		char *msg504;			/* message for error 504 */
-		int len504;			/* message length for error 504 */
-	} errmsg;
+	struct chunk errmsg[HTTP_ERR_SIZE];	/* default or customized error messages for known errors */
 };
 
 extern struct proxy *proxy;