REORG: include: move activity to haproxy/

This moves types/activity.h to haproxy/activity-t.h and
proto/activity.h to haproxy/activity.h.

The macros defining the bit field values for the profiling variable
were moved to the type file to be more future-proof.
diff --git a/src/ev_poll.c b/src/ev_poll.c
index 7239732..0d0c147 100644
--- a/src/ev_poll.c
+++ b/src/ev_poll.c
@@ -24,7 +24,7 @@
 
 #include <types/global.h>
 
-#include <proto/activity.h>
+#include <haproxy/activity.h>
 #include <proto/fd.h>