[Settings] Adding date format with conditional logic, HTML and localization refactoring

- Updating settings HTML to wrap date related settings within a div with class "section" and provide a heading, same treatment for time related settings
- Added date format to settings HTML with conditional `ng-show`
- Refactored translation.json to group date related copy and time related copy and updated settings HTML accordingly
- Settings controller updated to $watch `dateRange` to apply conditional logic for handling `dateFormat`
- Updated e2e tests to correct a default value and check for dateFormat to be hidden on load
Merge pull request #9 from stulees/master

[Settings] Adding date format with conditional logic, HTML and localization refactoring