This is a huge change, which includes some changes to replace code that
originally cloned to reuse allocations instead. The updated
`elastic-array` crate renames its consuming `Vec`-conversion method to
`into_vec`, which means that I can do a simple
`sed -i 's/to_vec/into_vec/'` and then fix the compilation errors.
This commit is probably a minor performance win and definitely a
significant readability win.
* 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
