REORG: include: move connection.h to haproxy/connection{,-t}.h

The type file is becoming a mess, half of it is for the proxy protocol,
another good part describes conn_streams and mux ops, it would deserve
being split again. At least it was reordered so that elements are easier
to find, with the PP-stuff left at the end. The MAX_SEND_FD macro was moved
to compat.h as it's said to be the value for Linux.
diff --git a/src/tcp_rules.c b/src/tcp_rules.c
index 1820ce5..6b51be4 100644
--- a/src/tcp_rules.c
+++ b/src/tcp_rules.c
@@ -13,6 +13,7 @@
 #include <haproxy/api.h>
 #include <haproxy/capture-t.h>
 #include <common/cfgparse.h>
+#include <haproxy/connection.h>
 #include <haproxy/global.h>
 #include <haproxy/list.h>
 #include <haproxy/sample.h>
@@ -22,11 +23,9 @@
 #include <haproxy/time.h>
 
 #include <haproxy/arg-t.h>
-#include <types/connection.h>
 
 #include <proto/acl.h>
 #include <proto/channel.h>
-#include <proto/connection.h>
 #include <proto/log.h>
 #include <proto/proxy.h>
 #include <proto/stick_table.h>