added a "test mode" for aos::Die and used it

ipc_stress_test was getting slowed down by disk I/O because of the
aos_fatal_error files getting written to /tmp and the stdout messages
that gtest doesn't capture were annoying, so I added a setting for
aos::Die to not do those things and used it in the ipc_stress_test
tests.
diff --git a/aos/common/common.gyp b/aos/common/common.gyp
index f3b4e69..f73f1f6 100644
--- a/aos/common/common.gyp
+++ b/aos/common/common.gyp
@@ -156,6 +156,7 @@
         'queue_testutils',
         'queue_test_queue',
         '<(AOS)/common/util/util.gyp:thread',
+        'die',
       ],
     },
     {
@@ -272,6 +273,7 @@
         '<(EXTERNALS):gtest',
         'mutex',
         '<(AOS)/build/aos.gyp:logging',
+        'die',
       ],
     },
     {
@@ -289,6 +291,7 @@
         '<(AOS)/build/aos.gyp:logging',
         'queue_testutils',
         '<(AOS)/atom_code/ipc_lib/ipc_lib.gyp:core_lib',
+        'die',
        ],
     },
     {