Prevent "<application> quit unexpectedly" message on sigquit
Solution 1:
If you never want to see the crash report dialogs, there is a preference to disable them:
defaults write com.apple.CrashReporter DialogType none
Log out and back in to apply the changes.
Solution 2:
You can also make the message appear as a notification instead:
defaults write com.apple.CrashReporter UseUNC 1