Log Message:
libretro-gambatte: Update to 20181022

Changes:

* Add optional 'dark filter' (a.k.a. eye saver, for use with games with white \ 
backgrounds)
* Add the option to only apply colour correction when running a GBC game or \ 
using a GBC colour palette
* Add 'accurate' colour correction method derived from Pokefan531's gbc-colour shader
* Add palettes for original Game Boy, Game Boy Pocket and Game Boy Light
* Add SGB palettes
* Alter memory descriptors to accommodate bankswitched RAM size