v0.8.0 Add Arc,Rc,Cow ,Improve performance

• Add Arc,Rc,Cow
• remove plugin features, Expand it in the way of rust, this is more rustly.
• more unit test ,this is different from integration testing
• Improve performance, some aspects
• The pub symbol of many fields has been removed in struct
• Support STS with trait type
• start use cargo fmt, format all code
• remove some clone, not just because Arc, Rc, Cow