DOC: Be more explicit about configurable check ok/error/timeout status

It is possible to configure the check status on success, on error and on
timeout, for http-check and tcp-check expect rules. But the documentation relies
on internal names. These names are reported on the stats and are describe in the
management guide. But it is probably a good idea to be more explicit too in the
doc describing these options.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 8ddd43f..40dae3f 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -4530,23 +4530,29 @@
     ok-status <st>     is optional and can be used to set the check status if
                        the expect rule is successfully evaluated and if it is
                        the last rule in the tcp-check ruleset. "L7OK", "L7OKC",
-                       "L6OK" and "L4OK" are supported and may be used to set,
-                       respectively, HCHK_STATUS_L7OK, HCHK_STATUS_L7OKCD,
-                       HCHK_STATUS_L6OK or HCHK_STATUS_L4OK success status.
-                        By default "L7OK" is used.
+                       "L6OK" and "L4OK" are supported :
+                         - L7OK  : check passed on layer 7
+                         - L7OKC : check conditionally passed on layer 7, for
+                                   example 404 with disable-on-404
+                         - L6OK  : check passed on layer 6
+                         - L4OK  : check passed on layer 4
+                       By default "L7OK" is used.
 
     error-status <st>  is optional and can be used to set the check status if
                        an error occurred during the expect rule evaluation.
-                       "L7RSP", "L7STS", "L6RSP" and "L4CON" are supported and
-                       may be used to set, respectively, HCHK_STATUS_L7RSP,
-                       HCHK_STATUS_L7STS, HCHK_STATUS_L6RSP or HCHK_STATUS_L4CON
-                       error status. By default "L7RSP" is used.
+                       "L7RSP", "L7STS", "L6RSP" and "L4CON" are supported :
+                         - L7RSP : layer 7 invalid response - protocol error
+                         - L7STS : layer 7 response error, for example HTTP 5xx
+                         - L6RSP : layer 6 invalid response - protocol error
+                         - L4CON : layer 1-4 connection problem
+                       By default "L7RSP" is used.
 
     tout-status <st>   is optional and can be used to set the check status if
                        a timeout occurred during the expect rule evaluation.
-                       "L7TOUT", "L6TOUT", and "L4TOUT" are supported and may
-                       be used to set, respectively, HCHK_STATUS_L7TOUT,
-                       HCHK_STATUS_L6TOUT or HCHK_STATUS_L4TOUT timeout status.
+                       "L7TOUT", "L6TOUT", and "L4TOUT" are supported :
+                         - L7TOUT : layer 7 (HTTP/SMTP) timeout
+                         - L6TOUT : layer 6 (SSL) timeout
+                         - L4TOUT : layer 1-4 timeout
                        By default "L7TOUT" is used.
 
     on-success <fmt>   is optional and can be used to customize the
@@ -10209,23 +10215,29 @@
     ok-status <st>     is optional and can be used to set the check status if
                        the expect rule is successfully evaluated and if it is
                        the last rule in the tcp-check ruleset. "L7OK", "L7OKC",
-                       "L6OK" and "L4OK" are supported and may be used to set,
-                       respectively, HCHK_STATUS_L7OK, HCHK_STATUS_L7OKCD,
-                       HCHK_STATUS_L6OK or HCHK_STATUS_L4OK success status.
+                       "L6OK" and "L4OK" are supported :
+                         - L7OK  : check passed on layer 7
+                         - L7OKC : check conditionally passed on layer 7, for
+                                   example 404 with disable-on-404
+                         - L6OK  : check passed on layer 6
+                         - L4OK  : check passed on layer 4
                         By default "L7OK" is used.
 
     error-status <st>  is optional and can be used to set the check status if
                        an error occurred during the expect rule evaluation.
-                       "L7RSP", "L7STS", "L6RSP" and "L4CON" are supported and
-                       may be used to set, respectively, HCHK_STATUS_L7RSP,
-                       HCHK_STATUS_L7STS, HCHK_STATUS_L6RSP or HCHK_STATUS_L4CON
-                       error status. By default "L7RSP" is used.
+                       "L7RSP", "L7STS", "L6RSP" and "L4CON" are supported :
+                         - L7RSP : layer 7 invalid response - protocol error
+                         - L7STS : layer 7 response error, for example HTTP 5xx
+                         - L6RSP : layer 6 invalid response - protocol error
+                         - L4CON : layer 1-4 connection problem
+                       By default "L7RSP" is used.
 
     tout-status <st>   is optional and can be used to set the check status if
                        a timeout occurred during the expect rule evaluation.
-                       "L7TOUT", "L6TOUT", and "L4TOUT" are supported and may
-                       be used to set, respectively, HCHK_STATUS_L7TOUT,
-                       HCHK_STATUS_L6TOUT or HCHK_STATUS_L4TOUT timeout status.
+                       "L7TOUT", "L6TOUT", and "L4TOUT" are supported :
+                         - L7TOUT : layer 7 (HTTP/SMTP) timeout
+                         - L6TOUT : layer 6 (SSL) timeout
+                         - L4TOUT : layer 1-4 timeout
                        By default "L7TOUT" is used.
 
     on-success <fmt>   is optional and can be used to customize the