Added public files

Roughly added all public files. Probably missed some, though.
diff --git a/sys/signals.h b/sys/signals.h
new file mode 100644
index 0000000..be4412e
--- /dev/null
+++ b/sys/signals.h
@@ -0,0 +1,23 @@
+#ifndef LPC_SIGNALS_H_
+#define LPC_SIGNALS_H_ 1
+
+// Our defines for some POSIX signals the driver defers to the mudlib.
+// This abstraction is intentional.
+#define LPC_SIGHUP    1
+#define LPC_SIGINT    2
+#define LPC_SIGTERM   15
+#define LPC_SIGUSR1   16
+#define LPC_SIGUSR2   17
+
+// __STD__ is defined during the driver compilation (the driver includes this
+// file as well) but not in LPC programs. In LPC we may safely define the
+// signals name without the LPC_ prefix.
+#if !defined(__STDC__)
+#define SIGHUP       LPC_SIGHUP
+#define SIGINT       LPC_SIGINT
+#define SIGTERM      LPC_SIGTERM
+#define SIGUSR1      LPC_SIGUSR1
+#define SIGUSR2      LPC_SIGUSR2
+#endif // __STD__
+
+#endif /* LPC_SIGNALS_H_ */