Begin incorporating Python unit tests into build

We now build a separate APE binary for each test so they can run in
parallel. We've got 148 tests running fast and stable so far.

third_party/python/Lib/dummy_threading.py

@@ -77,26 +77,28 @@ finally:
     del _dummy_thread
     del sys_modules
 
-Barrier = Barrier
-BoundedSemaphore = BoundedSemaphore
-BrokenBarrierError = BrokenBarrierError
-Condition = Condition
-Event = Event
-Lock = Lock
-RLock = RLock
-Semaphore = Semaphore
-TIMEOUT_MAX = TIMEOUT_MAX
-Thread = Thread
-ThreadError = ThreadError
-Timer = Timer
-WeakSet = WeakSet
-activeCount = activeCount
-active_count = active_count
-currentThread = currentThread
-current_thread = current_thread
-get_ident = get_ident
-local = local
-main_thread = main_thread
-setprofile = setprofile
-settrace = settrace
-stack_size = stack_size
+if __name__ == 'PYOBJ.COM':
+    Barrier = 0
+    BoundedSemaphore = 0
+    BrokenBarrierError = 0
+    Condition = 0
+    Event = 0
+    Lock = 0
+    RLock = 0
+    Semaphore = 0
+    TIMEOUT_MAX = 0
+    Thread = 0
+    ThreadError = 0
+    Timer = 0
+    WeakSet = 0
+    activeCount = 0
+    active_count = 0
+    currentThread = 0
+    current_thread = 0
+    enumerate = 0
+    get_ident = 0
+    local = 0
+    main_thread = 0
+    setprofile = 0
+    settrace = 0
+    stack_size = 0