POC5ToPOC6ChangeLog

1. Block target time moved from 42 seconds to 5 seconds.

2. Added block uncles reward (this probably existed in POC5, I just didn't see it for some reason).

3. Block synchronization changed (use GetBlockHashes, BlockHashes, GetBlocks, Blocks now, and the request is done in two phases, first get hashes then blocks.  A lot of the logic changed, and a list of needed items was added to the context).

4. codeHash is stored as a single zero in AddressState if blank, rather than the hash of an empty bytestring.

5. Starting difficulty is now 0x20000.

6. If transaction "to" address is blank, it is encoded as number 0, not 20 bytes (160 bits) worth of zeros.

7. "Hello" message has changed....  Capabilities are stored as an array of strings now.

8. Other new messages added: "Status" and "WhisperProtocolVersion".  Corresponding logic had to change a litte bit.



Also, I performed a bunch of cleanup.