Moving to binary format, custom_to_json.js -> custom_to_js.js
Pass in decoded packet to TransactionMachine process_packet.
Let the caller do the decoding in case it wants to save the
result, and pass the decoded packet instead of the raw packet.
Use a more compact binary representation for the packet data.
Updates for binary packet format.

Still a bit messy about decoding packets, if it is just done once
or done on demand, etc.
Move everything to binary format.
Dragon drop
Process in chunks to keep the browser alive.
Remove keyboard debug and use stopprop.
Try to use less memory by not keeping the parsed packet.
Handle "chunked" data differently.
Renable transfers now that memory usage is a bit better.