REORG: split "protocols" files into protocol and listener

It was becoming confusing to have protocols and listeners in the same
files, split them.
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 2e775d9..e28f808 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -47,7 +47,7 @@
 #include <proto/freq_ctr.h>
 #include <proto/log.h>
 #include <proto/pipe.h>
-#include <proto/protocols.h>
+#include <proto/listener.h>
 #include <proto/proto_uxst.h>
 #include <proto/proxy.h>
 #include <proto/session.h>