Web UI: housekeeping
UseService: as App.userService
Lots of changes, see the details

* Moved all the JSHint’s inline /*global*/ directives into jshintrc.json
* switched to a custom querySelector that throws when nothing found
* trigger authentication-related events on App.userService; removed
checkSession
* inlined client-list-ui.js
* logout without page refresh
Merge branch 'web-ui-refactoring'