Added tutorials 2, 3 and 4
Changed most of the discussion to use any_connection
Added examples on disabling TLS, multi-function operations, multi-queries and transactions
All examples now use any_connection
Automate parts of example qbk generation
Partially addresses #365 and #366
Please use asio::cancel_after, instead.
Replaced client_errc::timeout, client_errc::cancelled by
client_errc::no_connection_available, client_errc::pool_cancelled
async_get_connection no longer uses the last connect error code as failure error code,
but embeds this info in the output diagnostics
close#349
Thread-safety is now achieved using pool_params::thread_safe.
Removed pool_executor_params::thread_safe
Unsafe pools now use the standard Asio semantics
Safe pools are now safe even if the handlers' associated executors point
to a context different from the pool's context
close#268
Introduced BOOST_MYSQL_DISABLED_SERVER_FEATURES env var
Removed BOOST_MYSQL_NO_UNIX_SOCKET_TESTS env var
JSON tests in database_types are now actually run
close#29
Separate compilation
Immediate completions are now posted through the I/O executor
Jamfiles now correctly requires C++11
Refactored the protocol and channel modules
Removed example on default completion tokens
close#23close#112
