Merge pull request #18 from AndyYou/master

fixed issue of foreignkey constraints and add testing example
Merge pull request #19 from AndyYou/master

accomplish Recursive
Merge pull request #20 from AndyYou/master

Add Fill method
Merge pull request #21 from AndyYou/master

Accomplish If database no exists condition
Merge pull request #22 from AndyYou/master

deal transfer progress
Update txtLog
Merge pull request #9 from CalvertYang/master

Update txtLog finished