Release v4.0.0

realease version 3.5.0

Update CHANELOG.md

release version 2.5.0

Merge branch 'master' of github.com:alibaba/SmartEngine

fix database pattern bug: id assign missed issue

add extension load priority , fix user task extensionelements missed bug

Merge pull request #6 from alibaba/v2.0.4

V2.0.4