MEDIUM: checks: Implement default TCP check using tcp-check rules

Defaut health-checks, without any option, doing only a connection check, are now
based on tcp-checks. An implicit default tcp-check connect rule is used. A
shared tcp-check ruleset, name "*tcp-check" is created to support these checks.
diff --git a/include/types/checks.h b/include/types/checks.h
index a3652dd..3ebeaa8 100644
--- a/include/types/checks.h
+++ b/include/types/checks.h
@@ -354,7 +354,8 @@
 #define TCPCHK_RULES_SSL3_CHK    0x00000070
 #define TCPCHK_RULES_AGENT_CHK   0x00000080
 #define TCPCHK_RULES_SPOP_CHK    0x00000090
-/* Unused 0x000000A0..0x00000F00 (reserverd for futur proto) */
+/* Unused 0x000000A0..0x00000FF0 (reserverd for futur proto) */
+#define TCPCHK_RULES_TCP_CHK     0x00000FF0
 #define TCPCHK_RULES_PROTO_CHK   0x00000FF0 /* Mask to cover protocol check */
 
 /* A list of tcp-check vars, to be registered before executing a ruleset */