Add custom empty table cells for Candidate Details
Add template class for empty handling of single-section table views

To use:
  - Set self.tableView.dataSource to an instance of this class
    if the table view has no data to display.
  - Inspired by:
    http://blog.yangmeyer.de/blog/2013/05/11/best-practice-handling-empty-table-views
Add VIPEmptyCell model + xib
Implement VIPEmptyTableViewDataSource with custom cell xib
Implement VIPEmptyTableViewDataSource for Ballot/Details views
Implement VIPEmptyTableViewDataSource for FindElections View
Implement VIPEmptyTableViewDataSource for PollingLocations table view
Add descriptions to localized strings
Add empty table cells for Contest Details view
Spacing
NSString reference and spacing
Merge pull request #54 from flibbertigibbet/feature/add-localization-string-descriptions

Add descriptions to localized strings
Merge branch 'develop' into feature/empty-table-errors
Update PR with feedback

  - Add NSLocalizedString comments
  - Refactor setEmptyMessage
Merge branch 'feature/empty-table-errors' into develop
Refactor app to use AppSettings.h
Basic styling for most view controllers

Begins the styling process with the following:
  - Proper UITabBarItem colors for normal/selected states
  - Darkens the UINavigationBar to the dark blue of the top of the bg
    image
  - Sets the bg image for each view controller via a superclass
  - Sets the default UILabel text color to white for all UILabels
    inside a UITableViewCell
  - Proper header colors for Ballot & Details views
  - Styled about this app section
Update SocialMedia icons
Update candidate default blank image

Also deleted old placeholder social media/candidate default images