Added new process-pool runner based on AMPoule (integrated into Evennia).

This allows e.g. utils.utils.run_async to offload long-running functions
to a completely different subprocess entirely, offering real parallelism.

Implementation is still experimental, notably not all objects can be
transferred safely across the wire; also there is no concept of
updating caches yet - so adding an object from the subprocess side
will not be known in the main thread yet (since caches cannot yet tell
the underlying database has changed).

src/utils/idmapper/base.py

@@ -128,6 +128,11 @@ class SharedMemoryModel(Model):
         cls.__instance_cache__ = {} #WeakValueDictionary()
     flush_instance_cache = classmethod(flush_instance_cache)
 
+    def save(cls, *args, **kwargs):
+        "overload spot for saving"
+        super(SharedMemoryModel, cls).save(*args, **kwargs)
+
+
 # Use a signal so we make sure to catch cascades.
 def flush_cache(**kwargs):
     for model in SharedMemoryModel.__subclasses__():