Avoid allocating new object per default transform
Fix returning 0 size for GifBitmapWrapper
Pool and reuse GenericRequest objects.
Don't allocate ArrayList for single transformation
Don't allocate List for single cb in EngineJob.
Use priorities for requests fulfilled from cache.
Pool BitmapFactory.Options in downsampler.
Reduce some cache overhead in FlickrModelLoader
Add some logs for timing requests.
Only preload small thumbnails.
Improve thumbnail performance.
Fix lint warning.