Replace #621Fixed race condition between operation cancelation and loading finish
Update MKAnnotationView+WebCache.m

Replace deprecated method call
Merge pull request #794 from vjyanand/master

Update MKAnnotationView+WebCache.m
Merge pull request #783 from bpoplauschi/race_condition

Replace #621Fixed race condition between operation cancelation and loading finish
No need for explicit ivar and getters, as long as we have the @synthesize in place
#625 In order to fix the deadlock, reviewed the `[SDImageCache diskImageExistsWithKey:]` method. Based on the Apple doc for NSFileManager, using the defaultManager without the dispatch on the ioQueue to avoid the deadlocks. This instance is thread safe. Also created an async variant of this method `[SDImageCache diskImageExistsWithKey:completion:]`
For consistency, added async methods in `SDWebImageManager` `cachedImageExistsForURL:completion:` and `diskImageExistsForURL:completion:`
Replace #699 Fixed race condition in SDWebImageManager if one operation is cancelled, the completion block must not be called, otherwise it might race with a newer completion for the same object

Conflicts:
	SDWebImage/SDWebImageManager.m
Updated podspec version to 3.7.0
Update to #732 to fix misspell (completion instead of completition)
Merge branch 'master' of https://github.com/rs/SDWebImage