Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibC/sys/wait.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+#define WEXITSTATUS(status) (((status)&0xff00) >> 8)
+#define WTERMSIG(status) ((status)&0x7f)
+#define WIFEXITED(status) (WTERMSIG(status) == 0)
+#define WIFSIGNALED(status) (((char)(((status)&0x7f) + 1) >> 1) > 0)
+
+#define WNOHANG 1
+#define WUNTRACED 2
+#define WSTOPPED WUNTRACED
+#define WEXITED 4
+#define WCONTINUED 8
+
+pid_t wait(int* wstatus);
+
+__END_DECLS