Enabled a "Reaction" plugin

At @Rick.A’s request, I’ve enabled a reaction plugin for the site. You should see a little emoji icon at the bottom of posts that you can select from a limited number of reactions to a post if you want to convey appreciation to the post but don’t have a meaningful comment to make. The emojis are currently limited to thumbs up/down, laughing or anger.

I miss some points of expressiveness having just: :+1: :-1: :laughing: :heart: :rage:

@Garry Can we have this full set of 8? (the only modification to your set was removing rage and toning it down a bit inserting angry instead). The order is from the most positive towards the most negative.

:heart: :+1: :laughing: :thinking: :open_mouth: :cry: :-1: :angry:

:heart: :+1: :laughing: :thinking: :open_mouth: :cry: :-1: :angry:

Fixed.