Add headers to enable compiling without the libtorrent change

src/thread_base.cc

@@ -5,6 +5,7 @@
 #include <cassert>
 #include <cstdlib>
 #include <cstring>
+#include <mutex>
 #include <rak/error_number.h>
 #include <torrent/exceptions.h>
 #include <torrent/torrent.h>

src/thread_worker.h

@@ -37,6 +37,7 @@
 #ifndef RTORRENT_THREAD_WORKER_H
 #define RTORRENT_THREAD_WORKER_H
 
+#include <atomic>
 #include "thread_base.h"
 
 #include <rak/priority_queue_default.h>