Merge pull request #43 from fanjizhao/master

Fixed issue-40 and issue-41
错别字
错别字
Merge pull request #58 from layerssss/patch-1

fix typo
Merge pull request #59 from layerssss/patch-2

fix typo. thanks to layerssss.
第一次对nginx进行贡献，修改appendix_a.rst中的错别字
Merge pull request #70 from XueliangHan/master

thanks to Xuelianghan