Simplify tx.validate() and transaction::aggregate() (#1436)

* simplify tx validation and aggregation
we *only* need to account for reward when building a block from txs

* rustfmt

* cleanup and tests passing

* rustfmt

* better comments in with_reward()

* fix wallet tests

wallet/src/libtx/build.rs

@@ -299,7 +299,7 @@ mod test {
 			&keychain,
 		).unwrap();
 
-		tx.validate(false).unwrap();
+		tx.validate().unwrap();
 	}
 
 	#[test]
@@ -319,7 +319,7 @@ mod test {
 			&keychain,
 		).unwrap();
 
-		tx.validate(false).unwrap();
+		tx.validate().unwrap();
 	}
 
 	#[test]
@@ -333,6 +333,6 @@ mod test {
 			&keychain,
 		).unwrap();
 
-		tx.validate(false).unwrap();
+		tx.validate().unwrap();
 	}
 }

wallet/src/libtx/slate.rs

@@ -398,7 +398,7 @@ impl Slate {
 		final_tx.kernels()[0].verify()?;
 
 		// confirm the overall transaction is valid (including the updated kernel)
-		let _ = final_tx.validate(false)?;
+		let _ = final_tx.validate()?;
 
 		self.tx = final_tx;
 		Ok(())

wallet/src/libwallet/internal/tx.rs

@@ -196,7 +196,7 @@ where
 
 	// finalize the burn transaction and send
 	let tx_burn = build::transaction(parts, &keychain)?;
-	tx_burn.validate(false)?;
+	tx_burn.validate()?;
 	Ok(tx_burn)
 }