sytle : follow google python style for import module"

    the order should be
        standard
        3rd-package
        our-package

    and the package name should be in caseless and dictionary order
spider/ly_info : refine initial code of and add comment to ly_info
spider/ly_info : don't use reserved word
spider/ly_info : add dictionary structure comment
spider/ly_info : enable delay to avoid ddos protection
spider/npl_info : import order
spider/npl_ly : add variable and return data comment
doc : add program flow comment to readme
Merge pull request #11 from cmchao/refine_and_doc

Thanks to @cmchao dedicated help, these commits are really valuable.