Far too many changes to track, but the key ones are:

1. rewrite of the Haven variation of the Pricing Record class to support:
   - versioning of the PR format
   - nested supply_data and asset_data structs
   - verification of the signature using a variable-length string (not R+S)

2. calculation of the slippage tallies for a block in add_block(), so that
   we can work out the yield that is due to be paid out for the block.

Loads of little fixes and cleanups.

src/rpc/core_rpc_server.cpp

@@ -2935,6 +2935,7 @@ namespace cryptonote
       COMMAND_RPC_GET_CIRCULATING_SUPPLY::supply_entry se(i.first, std::to_string(i.second));
       res.supply_tally.push_back(se);
     }
+    res.height = m_core.get_current_blockchain_height();
     res.status = CORE_RPC_STATUS_OK;
     return true;    
   }