Zelda Initial Support

Initial support for the Zelda game and watch. Features are pretty bare-bones right now, but it'll allow you to launch retro-go.

Breaking Changes

Firmware files must now have the following names: internal_flash_backup_${DEVICE}.bin and flash_backup_${DEVICE}.bin, where DEVICE is one of {"mario", "zelda"}. For example, if you are patching the mario game and watch, the files should be named internal_flash_backup_mario.bin and flash_backup_mario.bin in the root directory of this project.