Set ios deployment target to 7.0
Merge pull request #1191 from acf/2.0

Set ios deployment target to 7.0
Making JSON a default response serializer for AFHTTPClient
Commenting out EventSource completion block code for further review
Ignoring deprecation warnings for text sizing
Adding responseSerializers property to UIImageView category

Switching from task back to request operation-backed image loading, to allow per-image view response serializers
Adding notifications for task starting and finishing
Updating README
Adding documentation for AFSerialization
Bumping version to 2.0.0-RC1
Fixing OSX deployment target in podspec