[WIP] txpool (tx validation) using block sums for full validation (#1567)

tx validation (txpool) rework/simplify

servers/src/mining/mine_block.rs

@@ -109,7 +109,12 @@ fn build_block(
 	let difficulty = consensus::next_difficulty(diff_iter).unwrap();
 
 	// extract current transaction from the pool
-	let txs = tx_pool.read().unwrap().prepare_mineable_transactions();
+	// TODO - we have a lot of unwrap() going on in this fn...
+	let txs = tx_pool
+		.read()
+		.unwrap()
+		.prepare_mineable_transactions()
+		.unwrap();
 
 	// build the coinbase and the block itself
 	let fees = txs.iter().map(|tx| tx.fee()).sum();
@@ -121,14 +126,7 @@ fn build_block(
 	};
 
 	let (output, kernel, block_fees) = get_coinbase(wallet_listener_url, block_fees)?;
-	let mut b = core::Block::with_reward(
-		&head,
-		txs,
-		output,
-		kernel,
-		difficulty.clone(),
-		verifier_cache.clone(),
-	)?;
+	let mut b = core::Block::with_reward(&head, txs, output, kernel, difficulty.clone())?;
 
 	// making sure we're not spending time mining a useless block
 	b.validate(