* 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
* Replace gulp with webpack and npm scripts for JS compilation
* Set up Travis CI to commit compiled JS
* Restructure `js` directory; only one instance of npm, forum/admin are "submodules"
* Refactor JS initializers into Application subclasses
* Maintain partial compatibility API (importing from absolute paths) for extensions
* Remove minification responsibility from PHP asset compiler
* Restructure `less` directory
