This fork from https://github.com/cooljeanius/cocoadialog has changes to the project so it builds against 10.9/10.10.
Most importantly it contains a fix so cocoaDialog can display on a logouthook on 10.9+.
I have no idea what I am doing, I am not a cocoa programmer. I just hacked in some changes to the method that sets the panel float level. It's probably the completely wrong approach. Credit to this code: https://github.com/dayglojesus/filevaultsetup/blob/master/FileVault%20Setup/FVSAppDelegate.m#L278
Please feel free to submit PRs to fix whatever mistakes I've made.
###USE IT AT YOUR OWN RISK###