[Rd] R.app should ignore -psn command line argument (PR#5674)

[ellis at stat.harvard.edu]

Full_Name: Byron Ellis
Version: R 1.9.0
OS: OS X .3
Submission from: (NULL) (140.247.241.138)


Under OS X, when something is launched via "open" or the Dock or the Finder it
is passed a Process Serial Number argument in the form of -psn_*, which
generates a warning dialog when starting R.app.

Putting the following in src/unix/system.c:234 ignores that parameter:

#ifdef HAVE_AQUA
else if(!strncmp(*av,"-psn",4)) { }
#endif