Can not start a installer for Mac OS X because of the double run prevention function.

This problem is the Mac version of QTIFW-566.

Situation
1.Build a QtIFW in master branch
2.Create the installer using a folder of tutorial.
ex <QtIFW DIR>/examples/tutorial
http://goo.gl/nnfZrU
3.Run the installer
4.Dialog of the accompanying image is displayed, and installer.app can not be started.

Perhaps, is because the lock file can not be created in a double run prevention function.
From OS X Mavericks, I can no longer save files in the hoge.app folder.
Therefore, we can not create lock file.