Major changes, including Brotli and Lizard

- update of zstd-mt library
- add brotli v0.6.0
- add lizard v2.0
- xxhash is from zstd for lz4, lz5 and lizard now
- update also the documentation, where needed

C/brotli/enc/backward_references_hq.h

@@ -11,7 +11,7 @@
 
 #include "../common/constants.h"
 #include "../common/dictionary.h"
-#include <brotli/types.h>
+#include "../types.h"
 #include "./command.h"
 #include "./hash.h"
 #include "./memory.h"