New canonical transaction order code. Tested and working.

CanonicalTXSet acts much like a map, but sorts the transactions in a simple
order that makes them take fewer passed.

src/CanonicalTXSet.h

@@ -0,0 +1,53 @@
+#ifndef __CANONICAL_TX_SET_
+#define __CANONICAL_TX_SET_
+
+#include <map>
+
+#include "uint256.h"
+#include "SerializedTransaction.h"
+
+class CanonicalTXKey
+{
+protected:
+	uint256 mAccount, mTXid;
+	uint32 mSeq;
+
+public:
+	CanonicalTXKey(const uint256& account, uint32 seq, const uint256& id)
+		: mAccount(account), mTXid(id), mSeq(seq) { ; }
+
+	bool operator<(const CanonicalTXKey&) const;
+	bool operator>(const CanonicalTXKey&) const;
+	bool operator<=(const CanonicalTXKey&) const;
+	bool operator>=(const CanonicalTXKey&) const;
+
+	bool operator==(const CanonicalTXKey& k) const	{ return mTXid == k.mTXid; }
+	bool operator!=(const CanonicalTXKey& k) const	{ return mTXid != k.mTXid; }
+};
+
+class CanonicalTXSet
+{
+public:
+	typedef std::map<CanonicalTXKey, SerializedTransaction::pointer>::iterator iterator;
+	typedef std::map<CanonicalTXKey, SerializedTransaction::pointer>::const_iterator const_iterator;
+
+protected:
+	uint256 mSetHash;
+	std::map<CanonicalTXKey, SerializedTransaction::pointer> mMap;
+
+public:
+	CanonicalTXSet(const uint256& lclHash) : mSetHash(lclHash) { ; }
+
+	void push_back(SerializedTransaction::pointer txn);
+	void erase(const iterator& it)	{ mMap.erase(it); }
+	void eraseInc(iterator& it);
+
+	iterator begin()				{ return mMap.begin(); }
+	iterator end()					{ return mMap.end(); }
+	const_iterator begin()	const	{ return mMap.begin(); }
+	const_iterator end() const		{ return mMap.end(); }
+	size_t size() const				{ return mMap.size(); }
+	bool empty() const				{ return mMap.empty(); }
+};
+
+#endif