状态码变更579 => 478
Merge pull request #203 from forrest-mao/doc/developer

状态码变更579 => 478
修改579
Merge pull request #204 from forrest-mao/doc/developer

修改478，添加579
增加文字水印文档及sample
Update form-upload.md
Merge branch 'master' of github.com:qiniu/developer.qiniu.com
Merge pull request #205 from forrest-mao/doc/developer

增加文字水印文档及sample
Merge pull request #206 from rwifeng/patch-20

Update form-upload.md
合并文档。
增加mkzip fop操作
add chgm to rs index
Merge pull request #207 from forrest-mao/doc/developer

增加mkzip fop操作
Merge branch 'master' of github.com:qiniu/developer.qiniu.com