peer discovery
ZNPeer class
message header parsing
message payload parsing
version message
bitcoin protocol handshake works
remove peers that fail to respond
fixed bug in input stream parser
addr message handling
tx message handler
bloom filter
inv message
merkleblock message
merkleblock proof-of-work verification
removed test code
proof-of-work validation
chain download sequence working
concurrent block download and block processing, moved coredata to a private queue
moved coredata usage out of ZNPeer
improved chain dowload performance