Allow users to access different reply modes from the composer.
Actions introduced:
- reply_as_new_topic
- reply_as_private_message
- reply_to_topic
- reply_as_whisper/not
* FIX: broken select badge as user title
* selected id wasn’t pass to underlying component
* <none> was rendered as an html tag <none></none>
* overriding a badge name wouldn’t work as it was using badge.name and not badge.display_name
* adds a spec to ensure this behavior is correct
* renames `select-box-kit` into `select-kit`
* introduces `single-select` and `multi-select` as base components
* introduces {{search-advanced-category-chooser}} as a better component for selecting category in advanced search
* improves events handling in select-kit
* recreates color selection inputs using {{multi-select}} and a custom {{selected-color}} component
* replaces category-selector by a component using select-kit and based on multi-select
* improves positioning of wrapper
* removes the need for offscreen, and instead use `select-kit-header` as a base focus point for all select-kit based components
* introduces a formal plugin api for select-kit based components
* introduces a formal pattern for loading and updating select-kit based components:
```
computeValue()
computeContent()
mutateValue()
```
Users can no longer opt-in for "public" edit history
if site owner disables it.
This feature adds cost and complexity to post rendering since
user options need to be premeptively loaded for every user in the
stream. It is also confusing to explain to communities with private edit
history.
