Integrate retrofit2, diskcache and androidThreadPool. Support REST & URL. Fix image OOM. Provide GalleryAdapter instance.
Android Studio 2.3, Gradle 3.3
com.jakewharton:disklrucache:2.0.2, com.squareup.retrofit2:retrofit:2.2.0, com.github.chrisbanes:PhotoView:1.3.1
ApiService:Should define REST api path base on real environment. BaseUrl:Should define url base on real environment.