Add option to disable Emoji/Emoticon Autocomplete

Some languages use the ":" differently, and the Emoji/Emoticon autocompletion complicates this. There is currently an option to disable the whole "Autocomplete" for each user, but that also disables the use of "[", "//", "@", etc.

It would be great to have the option to disable the Autocompletion for only Emojis/Emoticons, both for each user and globally by an administrator.