* 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()
```
* Add user_home configuration option
* Use the new user_home preference to actually show the right home page
* Fix trailing whitespace
* Update user_option_serializer.rb
* Fix JavaScript default homepage tests
* Use an object instead of a giant switch
* Remove trailing whitespace
* Make the default `user_home` set to `null` instead of `0`
* Rename user_home to homepage_id
* Adds primary user group as a class to quote
This feature addition will add the class `group-PRIMARY_USER_GROUP` to
the quote `aside`. `PRIMARY_USER_GROUP` will be the primary user group
of the user being quoted. This is similar to the class that is added to
a `topic-post`.
* Remove trailing whitespace
* Fix avatar in test
* Address PR comments
* Fix trailing whitespace
This commit introduces a mutation on input value given to select-box-kit when value is empty. The refactoring required to avoid this would be too heavy atm, but ultimately we would want to avoid this.