Corresponds to bx v2.0.0 and client v2.0.0.

Corresponds to 1.0.10 in source, on branch frozen for obelisk and sx.

Re-signing v2.0 release with new PGP key:

http://libbitcoin.dyne.org/amir_taaki.pgp.asc

various fixes and improvements.

updated version.hpp

various small fixes.

small api changes.

libbitcoin 1.0 release for Debian inclusion.

Recent changes:
- message.hpp has moved to primitives.hpp and the message:: namespace removed.
- async_service renamed to threadpool.
- new leveldb backend (recommended). please switch over to this blockchain.
- logging subsystem has been made more extensible and configurable.