* fixed naming of rlp modules
* RlpStream cleanup
* appending short rlp lists (0...55 bytes) is 25% faster
* RlpStream does not use bytes module, nor trait Stream
* removed unused code from rlp module
* compiling ethcore-util with new rlp serialization
* compiling parity with new rlp serialization
* fixed compiling ethcore-light with new rlp serialization
* fixed compiling ethsync with new rlp serialization
* removed redundant comment, print
* removed redundant double-space
* replace usage of WriteBytesExt with ByteOrder
* CHT builder and prover
* use CHT abstraction in provider
* hide CHT internals from header chain
* fix itertools conflict by updating all to 0.5
* cht proof checker, use it in on_demand
Closes#2213
Omit transaction and receipt roots from abridged block.
No longer use RLP compression.
Make ordered_trie_root generic over an iterator to save an allocation.
Breaks snapshot format backwards compatibility (with other 1.4 snapshots -- it's already been broken with 1.3).
Documentation will need updating
