I also tried unrolling the 256-iteration loop further below, but it actually caused a
slowdown (my guess is either branch prediction stopped kicking in or the instruction
cache was being maculated).
* refactor PriceInfo to use Fetch and reuse the client
* forget Fetch future to keep it running in the background
* update Debug message for price_info::Client
* wrap underlying errors in price_info client
* use debug_struct in price_info client debug implementation
* use global fetch service in price_info client
* rename gas_pricer parameter in RunCmd
* move price_info to its own crate
* fix price_info tests
* replace rustc_serialize with serde_json in price_info
* add documentation for price_info
* remove unused rustc-serialize dependency from ethcore
* fix price_info formatting
* re-export fetch crate in price_info
* remove unused cfg attributes in price_info
* add tests for price_info
* whisper skeleton
* basic message store
* rallying and message logic
* pass host info to network protocol handlers
* choose who starts rally based on node key
* module reshuffling
* mining messages
* prune messages by low PoW until below size target
* associated error type for ethkey generators and `OsRng` generator
* beginnings of RPC
* generic message handler for whisper
* reshuffle code order
* standard payload encoding and decoding
* basic crypto
* minor restructuring of net code
* implement shh_post
* merge?
* implement filters
* rand trait for hash types
* filter RPCs for whisper
* symmetric encryption of payload
* pub-sub
* filter tests
* use only secure random IDs
* attach arbitrary protocols to network
* basic integration of whisper into Parity
* eagerly prune low PoW entries
* broadcast messages with salted topics
* node info RPC
* fix import
* fix leading zeros calculation
* address minor grumbles
