Fix #58: reconnect replica on connection errors
Implement FFI bindings for begin()/commit()/rollback().

Ensure a transaction is not left hanging around
when a session disconnects.

Add basic tests for transactions.
Merge branch 'master' of github.com:tarantool/tarantool
Merge remote-tracking branch 'origin/gh-58-replica-reconnect'
Fix #245: title 'primary' is meaningless in master-master mode
Implements gh-386; remove fiber.create(), fiber.resume(), fiber.detach()

Make status() a method.
Update the docs.
Merge branch 'master' of github.com:tarantool/tarantool
Merge branch 'master' of https://github.com/tarantool/tarantool