RESUtils.options.mixin(mixinKey, optionObject) and .mixins dictionary
RESUtils.options.mixins['subredditList']

list option
use subredditList options mixin in nightMode and filteReddit

nightMode.subredditStylesWhiteList
filteReddit.keywords, .domains, .flair, .allowNSFW
Merge pull request #1718 from andytuba/options-mixins

Options mixins