Add support for RGB_565 bitmaps to use less memory about fresco

[blackiedm]

you can see Modifying The Image

[tyronen]

We don't currently support this. We are considering adding RGB_565 for images that don't use alpha.

[nbarraille]

@blackiedm Using a Postprocessor wouldn't provide much, because the version of the image stored in the memory cache is the one before post processing from what I understand, so you will end up having to transform it back every time, and keep both versions in memory.
Plus I don't even know if changing the config of a bitmap instance is possible at all, as it changes the size of the underlying byte array
@tyronen I really hope this gets in soon, this would be super helpful for apps using a lot of images. The library looks pretty good so far, keep up the good work!

[nikslushkin]

We really need this feature for images without alpha. It will free 50% of its memory usage.

[tyronen]

This was added in v0.8.0.