Here is a brief list of things that still need to be done.

More unit tests:
   - Create a MockNetworkConnection and use it to test the Peer.

API:
   - Reorganize the package layout to be more modular.
   - Support multiple active wallets.
   - Allow sorting of transactions by time.

Protocol:
   - Start up faster
      - Store a block locator in the persisted chain
      - Use the getheaders command to speed up the initial chain download
   - Implement tx fees.
   - Longer term potentially add a getmerklebranch protocol command so we can check 0-confirmation transactions.
   - Support PeerGroups for holding open/using multiple connections at once.

Examples/documentation:
   - Implement a simple Swing GUI payment app.

Cleanup:
   - Find a way to avoid some horrid hacks when shutting down the network connection.
   - Implement a BitCoin class that encapsulates a BigInteger and formatting.
   - Make NetworkParameters use subclasses instead of static methods to construct.



==========

Impacts from Steves changes:
- Reformat affected files
- JavaDocs for the c'tors that take parseLazy/parseRetain
- Copyright header/correct author for EmptyMessage/ChildMessage
- Remove superfluous empty lines in ListMessage.java
- Remove VersionMessage check in Message serialization roundtrip checks
- Delete dead code in Message.checkParsed
- LazyParseByteCacheTest:
   - copyright/comments/unused things
   - debug prints
   - some redundant asserts
   - huge functions
   - dead code
- Magic number 36 in ListMessage.parseLite
- Manipulator.java needs docs
- Assert in Message c'tor needs an English version.
- Spelling in PeerAddress.bitcoinSerializeToStream
- SpeedTest has a lot of unused fields, large functions. See if it can be simplified/densified.
- Caching immutable lists?
- Dead code in Transaction.parse
- javadocs on Transaction{Input,Output,} getters

- Delete the code related to deduping. The new network management code to be checked in later makes it unnecessary.
  Also remove singleDigest as a result (it duplicates Sha256Hash).


Block.java:
- Reformat
- Replace magic number 80 with HEADER_SIZE_BYTES in Block.parseTransactions
- The parseLight stuff isn't clear without referring to superclass.
- Delete dead code in writeTransactions
- checkParse{Header,Transactions} should be maybeParse...
- immutableTransactions is misleading, it allows you to mutate the contents.
- Unit-test only getters should be package private.