Remove unused wrapping .system-folder class

* Alphabetize attributes for .system-caret
Display locale timestamp for task updatedAt

Using JavaScript’s `Date.prototype.toLocaleString`, the timestamp is
displayed in the user’s preferred locale format without using another
library.

Add `title` attribute so hovering the time gives the ISO timestamp.
Merge pull request #323 from mesosphere/locale-timestamps

Locale timestamps
Add Mousetrap for handling keyboard shortcuts

* Switch modal to use Mousetrap for “esc” rather than custom binding
* Bind to “c” globally for creating a new application
* Bind to “#” when the app modal is open to delete the app