Summary:
Use NSData as key
Add chunking of files
Add support for Animated Images
This adds support for GIF playback in ASDK. It's not currently ready
for merging to public ASDK – for one the GIF decompression may make
more sense in PINRemoteImage.
Removed duration as it wasn't used
Make cover image lazily loaded
Differential Revision: https://phabricator.pinadmin.com/D82033
Initial open-source release of ASMultiplexImageNode. Documentation and
example code forthcoming.
Note: ASMultiplexImageNode requires Xcode 6 to compile. Tests are now
compiled against the iOS 8 SDK and run on iOS 7.1 and iOS 8.
