precomputed block hashes are now in blocks of N (currently 256)

This shaves a lot of space off binaries

tests/unit_tests/ban.cpp

@@ -78,6 +78,7 @@ public:
   uint8_t get_hard_fork_version(uint64_t height) const { return 0; }
   cryptonote::difficulty_type get_block_cumulative_difficulty(uint64_t height) const { return 0; }
   bool fluffy_blocks_enabled() const { return false; }
+  uint64_t prevalidate_block_hashes(uint64_t height, const std::list<crypto::hash> &hashes) { return 0; }
 };
 
 typedef nodetool::node_server<cryptonote::t_cryptonote_protocol_handler<test_core>> Server;