MEDIUM: checks: Add a shared list of tcp-check rules

A global list to tcp-check ruleset can now be used to share common rulesets with
all backends without any duplication. It is mandatory to convert all specific
protocol checks (redis, pgsql...) to tcp-check healthchecks.

To do so, a flag is now attached to each tcp-check ruleset to know if it is a
shared ruleset or not. tcp-check rules defined in a backend are still directly
attached to the proxy and not shared. In addition a second flag is used to know
if the ruleset is inherited from the defaults section.
diff --git a/include/proto/checks.h b/include/proto/checks.h
index a0a8329..fb33746 100644
--- a/include/proto/checks.h
+++ b/include/proto/checks.h
@@ -62,6 +62,7 @@
 	LIST_ADDQ(&tcp_check_keywords.list, &kw_list->list);
 }
 
+void deinit_proxy_tcpcheck(struct proxy *px);
 /* Declared here, but the definitions are in flt_spoe.c */
 int spoe_prepare_healthcheck_request(char **req, int *len);
 int spoe_handle_healthcheck_response(char *frame, size_t size, char *err, int errlen);