CLEANUP: includes: fix includes for a number of users of fd.h
It appears that fd.h includes a number of unneeded files and was
included from standard.h, and as such served as an intermediary
to provide almost everything to everyone.
By removing its useless includes, a long dependency chain broke
but could easily be fixed.
diff --git a/include/proto/signal.h b/include/proto/signal.h
index ef43ef9..6556446 100644
--- a/include/proto/signal.h
+++ b/include/proto/signal.h
@@ -14,6 +14,7 @@
#include <signal.h>
#include <common/standard.h>
#include <types/signal.h>
+#include <types/task.h>
extern int signal_queue_len;
extern struct signal_descriptor signal_state[];