* Update Loading Indicator
- Fix mistake in LoadingIndicator Less
- Middle align the loading indicator when inline
- Fix Loading Indicator not correctly accepting container class names
- Add inline and block attributes
* Fix loading indicator in composer
* Fix loading indicator on notification list
* Fix loading indicator on discussion page
* Fix loading indicator on button
* Update more uses of loading indicator
* Fix loading indicator in Search box
* Fix AvatarEditor loading spinner
* Set default spinner props
* Replace "tiny" with "small" in Less
* Improve spinner vertical centring in buttons
* Reduce size specificity
* Use single attribute for block/inline
* Use new display attribute
* Use classes for different sizes
* Use `display=block` by default
- Get rid of Bootstrap (except we still rely on some JS)
- Use BEM class names
- Rework variables/theme config
- Fix various bugs, including some on mobile
The CSS is still not ideal – it needs to be cleaned up some more. But
that can be a focus for after beta.