Converted to ARCLite (required OSX 10.6 and Xcode 4.2 or above, 64bit only)
Clean up deprecatd API (replace filename method of NSSavePanel)
Changed singleton implementation. because static analyzer on Xcode wared potential problem
Inline function replace macro returned object because code completion is worked well
Added managed object subclass to property belonging to data model
Clean up deprecated API (beginSheetForDirectory... method of NSSavePanel class replace)