Close button sends client to the tray, statically linked Qt for OSX.
See the Changelog for list of features and fixes currently only available in the nightly builds.
I've tried posting a Mac version of ScarletFire's build before, but problems with the new Qt 5.1 deployment utility made the resulting package useless on all machines but mine. I've finally had time to look into it today, and thanks to some new information from around the web now that Qt 5.1 users with more time on their hands a much better understanding of Mac operating systems have run into the problem as well, I now have a package that appears to work on a secondary Snow Leopard virtual machine with no version of Qt installed:
Let me know how it works for you, and I'll do my best to fix any issues that come up.