Merge pull request #81 from heyongjian/ios-style

Ios style
Merge pull request #83 from heyongjian/ios-style

Ios style
fix bug :issue-39, when download a wallpaper, the wallpaper thumbnai applys the preview image.

modify the url of the wallpaper thumbnai image.
Merge pull request #170 from whuthm/ios-style

fix bug :issue-39, when download a wallpaper, the wallpaper thumbnai applys the preview image.