Fast IBD client improvements

[rustaceanrob]

• Block sizes are not evenly distributed throughout Bitcoin's history. Client's can take advantage of this by requesting many blocks from the early Satoshi client, and far less from recent history. One such way is a linear increase in request size as one progresses backwards along the header chain. Starting with 1,000 blocks, divide the block hashes by adding 1,000 blocks in each request until the range is empty. Requests would then have sizes: [1000, 2000, 3000, ... ~40000]. Request blocks in an uneven distribution #41
• The client needs configurations for Network, ChainType, path to .hints and path to where block files will be written. https://github.com/Kixunil/configure_me
• The header sync is bug-prone.
  • Drop a connection when getting an inv
  • Needs a flag to request a new header or not
• Pings should be adhered to a certain timeout.
• Other timeouts can be configured by a config file.
  • Minimum blocks/sec
  • hintfile binary