Highlights

Bumped Fresco's minSdk to 14. We did not remove any Gingerbread-specific code yet, but will do so soon. 091e8b7
Proper nullability annotations for some classes by using new Infer annotations - this improves Kotlin support and null-safety.
Improved Java-only Fresco setup. 4a99615
Lots of debug logging improvements: More reliable image origin, new MEMORY_BITMAP_SHORTCUT origin, more debug information available. These are available via ImagePerfData#getExtraData()
Added experimental option to recover from OOMs: f43d599
Added option to force a single image pipeline instance: 5f5c076
Disk cache support for the Fresco Flipper images plugin.
Bumped SoLoader version to 0.9.0.
Use buildSrc for Fresco's internal dependency management.
WIP: Lots of improvements for our new Fresco Vito UI components.

Pull requests:

Fixed resource leak problem while using BlurPostProcessor. Thanks @FrancescoJo for the PR.
Make sure there is at least one overlay in GenericDraweeHierarchy. Thanks @dengweichao for the PR.
Removed unused padding value. Thanks @erenulas for the PR.

Cleanup

Removed Drawee-Volley module. If you're using Drawee-Volley, you can still continue using it by just copying the files removed with 7c2517e into your project. We did not significantly change these in a long time, so this has been stable.
Removed OkHttp2 image pipeline artifact. See deba7d1