0.2.0-alpha.1

• The 0.1 version has an error not reported to the user #54
• There is a type of error using #54
• Lack of defense against fd attacks, need a timeout error #54 #57
• Some users want to be able to support event stream output instead of callback，0.2 should support both programming modes at the same time #58
• Let user control turn protocol on and off, breaking change #62
• May need to support each protocol has their own codec, and does not require the same structure(trait object) #63
• Add poll API to all protocol handle, to allow users to customize some stream tasks in the handle #65