Refactored constant names
Added log enable/disable option.
Implementation refactoring
More refactoring. Exposed +stopTracking and +openAppStore methods
Renamed +openAppStore with +openStore
Included basic verifications before starting track.
Disabled repeated setters if values set already.
Added support for ios7 new app store url
Implementation refactoring. Set itunes urls as constants.
Updated gitignore file.