Refs #1788
TypeError: t.showDeletionAlert is not a function
at onSuccess(./src/forum/utils/UserControls.js:104:12)
Also, don't override 'this' param with user object for editAction
* 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