Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/liblzma/delta/delta_common.h

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       delta_common.h
+/// \brief      Common stuff for Delta encoder and decoder
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_DELTA_COMMON_H
+#define LZMA_DELTA_COMMON_H
+
+#include "common.h"
+
+extern uint64_t lzma_delta_coder_memusage(const void *options);
+
+#endif