Project upgraded by Xcode 6.1.
Converting tests to XCTest.
Adding DuxTheme.m to tests to allow them to build.
Fixing warnings in tests.
Setting project-wide indentation to spaces.
Switching to 10.9 SDK.
Building against the 10.10 SDK prevents the text of DuxNavigatorFileCell to be drawn for some reason.
Exposing image property of DuxNavigatorFileCell.
Using image property via dot notation.
Fixing static analyser issues.
Updating XIBs with Xcode 6.1.
Just re-saving and building.
Fixing file column handling.
Fixing object value handling in DuxNavigatorFilesViewController.
Merge pull request #146 from JanX2/master

Modernization and fixes