Added and exposed some methods that allow to check if an image exists on disk without taking it off disk and decompressing it first. Makes for a nice performance boost when checking if many files exist in the disk cache already
Fixed styling to match rs/SDWebImage repo
Share schema so it can be used by Xcode bots
Only use the runloop with timeout on iOS 5 (fix #497)
Remove WebP support from default target and add a dedicated target

Too many people have issue with WebP library dependancy.
Merge pull request #498 from donholly/master

Added and exposed some methods that allow to check if an image exists on...
Merge branch 'master' of https://github.com/rs/SDWebImage
Merge branch 'master' into barz-master