Fix 'getAffectedAccount' -- logic was totally wrong.

You can't get this from the transaction because which accounts a transaction
affects depends on things like which offers it winds up taking. And you
can't build it with the metadata because you don't always build the metadata
locally -- consider fetching a ledger after a network split. The only
rational way to do this is to build the affected account vector from the
metadata.

src/cpp/ripple/TransactionMeta.h

@@ -49,7 +49,7 @@ public:
 	STObject& getAffectedNode(SLE::ref node, SField::ref type); // create if needed
 	STObject& getAffectedNode(const uint256&);
 	const STObject& peekAffectedNode(const uint256&) const;
-	//std::vector<RippleAddress> getAffectedAccounts();
+	std::vector<RippleAddress> getAffectedAccounts();
 
 
 	Json::Value getJson(int p) const { return getAsObject().getJson(p); }