workflow v0.11.1

New Features

• Add cancelable timer. You may name a timer and cancel by name.
• Add named mailbox task. You can send message to a mailbox task by it's name.
• Add WFFacilities::ReplyGuard as an alternive way to implement asynchronous server.
• Support kafka client over TLS.
• Support redis username for redis server 6.0.

Impovements

• Refactor named task's implementation to make it faster.
• Avoid stack overflow when running out of file discriptors.
• Optimize JSON parser by parsing JSON number manually. About 3 times faster than 'strtod()'.

Bug Fixes:

• Fix WFMySQLConnection crash bug when running multiple tasks concorrently.
• Fix kafka authentication bug by encoding for kafka SASL username and password.
• Fix kafka client bug that does not retry.
• Fix bug of 'WFTaskFactory::signal_by_name()' with 'max'.

Incompatible changes

• Timed thread/go task's state in callback was changed to WFT_STATE_SYS_ERROR with error ETIMEDOUT when timeout. The original state was WFT_STATE_ABORTED. Please check timeout by using 'if (task->get_state() != WFT_STATE_SUCCESS)', which is compatible with both behaviors.
• Remove WFMultiThreadTask.