bug fix for move to previous/next third
Add a Podfile and migrate to an actively maintained fork of Sparkle.

  - Incorporate functionality from the decommissioned ZeroKit project
  - Remove the ZeroKit submodule
Display the version of Spectacle in the title of the preferences window.
No need to check for the application version when setting the status item tool tip.
Combine SpectacleUtilities and ZKUtilities.
Remove ZKAccessibilityElementAdditions.
Spectacle should not attempt to interact with sheets.
Merge pull request #214 from arnaudl/thirds_bug

Use a fudge factor when determining whether a window can be resized to thirds.
Allow users to move windows with their mouse through the status menu.