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

No change was necessary. Include from wdt.c was dropped since unneeded.
diff --git a/src/ev_kqueue.c b/src/ev_kqueue.c
index a4c3bce..e1d74d6 100644
--- a/src/ev_kqueue.c
+++ b/src/ev_kqueue.c
@@ -18,6 +18,7 @@
 #include <sys/time.h>
 
 #include <haproxy/api.h>
+#include <haproxy/signal.h>
 #include <haproxy/thread-t.h>
 #include <haproxy/ticks.h>
 #include <haproxy/time.h>
@@ -26,7 +27,6 @@
 
 #include <haproxy/activity.h>
 #include <haproxy/fd.h>
-#include <proto/signal.h>
 
 
 /* private data */