Send SIGTERM, not SIGQUIT.

SIGTERM is the correct signal for a graceful exit.

This will hopefully resolve rails#9761.

railties/test/application/console_test.rb

@@ -127,7 +127,7 @@ def write_prompt(command, expected_output = nil)
   end
 
   def kill(pid)
-    Process.kill('QUIT', pid)
+    Process.kill('TERM', pid)
     Process.wait(pid)
   rescue Errno::ESRCH
   end