Change libpng version
更改libpng版本

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Fix sln title
修正sln标题

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Merge branch 'dev-2'

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>