Merge pull request #170 from whuthm/ios-style

fix bug :issue-39, when download a wallpaper, the wallpaper thumbnai applys the preview image.
wanghao:fix bug issue-40,the workspace area of the last row of icons, it will disappear after restart launcher
Merge pull request #172 from lwanghaol/ios-style

wanghao:fix bug issue-40,the workspace area of the last row of icons, it will disappear after restart launcher
Merge pull request #84 from heyongjian/ios-style

Ios style