XD-1375 First pass on UI redesign

* Theme the Spring XD UI to look like Spring.io
  - Use LESS and Bootstrap variables (as much as possible) to keep styles maintainable
* Provide very rudimentary login support (solely for supporting the UI)
* Provide responsive support
* Add fonts
  - Not using Google fonts via CDN as XD may be deployed without net-access
* Add quick filter to Definitions tab
* Add new background image to start page
* Upgrade Bootstrap to version `3.1.1`

Jira: https://jira.spring.io/browse/XD-1375

XD-1375 Add Spring XD Logo - Mobile Version

* Polish styles
* Update Spring XD Logo

XD-1375 Improve Growl CSS styling

XD-1375 Wrapping login and logout logic as modules

XD-1375 Fix CSS style import paths

XD-1375 Add template controller

XD-1375 Fix/update `angular-busy`

* Update `angular-busy` to version `3.0.2`
* Fix `angular-busy` not loaded as module
* Fix JS file changes not detected in sub-dirs by Grunt

XD-1375 Simplifying `index.html`

XD-1375 Add quick filter to Executions tab

* `$rootScope.authenticationEnabled = false;` will deactivate authentication visually as well
* Rename *Templates* to *Modules*
XD-1375 Changes on merge

- Rename job template -> job module
- Comment out ScheduleJobController route definiton and tab