Merge pull request #70 from libbitcoin/develop

Refine help and dispatch.
Merge pull request #74 from libbitcoin/develop

Update tests.
Rename watch-stealth, fetch-confirmations, update impl, tests. Reorder headers.
Merge pull request #77 from evoskuil/develop

Rename watch-stealth, fetch-confirmations, update impl, tests. Sort hdrs.
Merge pull request #78 from libbitcoin/develop

Promote develop.
Update libbitcoin_client dependency.