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/dec/bit_reader.h

@@ -11,7 +11,7 @@
 
 #include <string.h>  /* memcpy */
 
-#include <brotli/types.h>
+#include "../types.h"
 #include "./port.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)