nogui option ignored (osx)

On Mac OS X, the server appears to ignore the `nogui` option and fails to start due to inability to connect to the window server. (In this configuration, it would not be possible to access the window server since the machine is headless and being accessed over ssh.)

What I expected to happen was...:
As per documentation here and here, I would have expected this to lead to a successful server start, as it has in past versions.

What actually happened was...:
Uncaught java exception. Log is attached.

Steps to reproduce...:
1. ssh into Mac OS box with java installed.
2. Attempt to launch headless server (a minimal invocation seems to be java -jar minecraft_server.1.7.2.jar nogui).
3. Observe the resulting traceback with the error that there are insufficient permissions to connect to a window server.