Fix crash when dataSource is empty
Update SDWebImage to git head

Version 3.5.4 will lead to a compiling error.
Use sd_setImageWithURL instead of setImageWithURL
Make project compliant with xcode 6.1
Bug fix: syntax mistakes that cause slideshow duration cann't be customized.
Add support for reloading images
Merge pull request #2 from luohao-brian/master

Bug fix and enhancement against InfiniteSlideShow