Throw only BOOST_EXCEPTION() macro vs. actual boost exceptions.
Refactor address validate to avoid exceptions.
Support non-exception boost.
Define constants for no boost exceptions.
Add required namespace reference.
Merge pull request #112 from evoskuil/develop

Throw only BOOST_EXCEPTION() macro vs. actual boost exceptions.
Merge pull request #113 from libbitcoin/develop

Throw only BOOST_EXCEPTION() macro vs. actual boost exceptions.