btcd v0.3.3-alpha

• Significantly improve initial block chain download speed
  (#20)
• Add a new checkpoint at block height 267300
• Optimize most recently used inventory handling
  (#21)
• Optimize duplicate transaction input check
  (btcsuite/btcchain#2)
• Optimize transaction hashing
  (#25)
• Rework and optimize wallet listener notifications
  (#22)
• Optimize serialization and deserialization
  (#27)
• Add support for minimum transaction fee to memory pool acceptance
  (#29)
• Improve leveldb database performance by removing explicit GC call
• Fix an issue where Ctrl+C was not always finishing orderly database
  shutdown
• Fix an issue in the script handling for OP_CHECKSIG
• Impose max limits on all variable length protocol entries to prevent
  abuse from malicious peers
• Enforce DER signatures for transactions allowed into the memory pool
• Separate the debug profile http server from the RPC server
• Rework of the RPC code to improve performance and make the code cleaner
• The getrawtransaction RPC call now properly checks the memory pool
  before consulting the db (#26)
• Add support for the following RPC calls: getpeerinfo, getconnectedcount,
  addnode, verifychain
  (#13)
  (#17)
• Implement rescan websocket extension to allow wallet rescans
• Use correct paths for application data storage for all supported
  operating systems (#30)
• Add a default redirect to the http profiling page when accessing the
  http profile server
• Add a new --cpuprofile option which can be used to generate CPU
  profiling data on platforms that support it
• Several other minor performance optimizations
• Other minor bug fixes and general code cleanup