Add a --fluffy-blocks option to relay blocks as fluffy blocks

Defaults to off, but fluffy blocks are forced enabled on testnet

src/common/command_line.cpp

@@ -120,4 +120,9 @@ namespace command_line
   , "Check for new versions of monero: [disabled|notify|download|update]"
   , "notify"
   };
+  const arg_descriptor<bool> arg_fluffy_blocks  = {
+    "fluffy-blocks"
+  , "Relay blocks as fluffy blocks where possible (automatic on testnet)"
+  , false
+  };
 }