Fixes #7

* added a synchronous cluster simulation

* added a test for the sync function

* moved signing into its own module

* refactored imports to solve circular import problems stemming from the task module pretending to be a cluster

* added documentation for the new sync option

django_q/signing.py

@@ -0,0 +1,44 @@
+try:
+    import cPickle as pickle
+except ImportError:
+    import pickle
+
+from django.core import signing
+from django_q.conf import Conf
+
+BadSignature = signing.BadSignature
+
+class SignedPackage(object):
+    """
+    Wraps Django's signing module with custom Pickle serializer
+    """
+
+    @staticmethod
+    def dumps(obj, compressed=Conf.COMPRESSED):
+        return signing.dumps(obj,
+                             key=Conf.SECRET_KEY,
+                             salt='django_q.q',
+                             compress=compressed,
+                             serializer=PickleSerializer)
+
+    @staticmethod
+    def loads(obj):
+        return signing.loads(obj,
+                             key=Conf.SECRET_KEY,
+                             salt='django_q.q',
+                             serializer=PickleSerializer)
+
+
+class PickleSerializer(object):
+    """
+    Simple wrapper around Pickle for signing.dumps and
+    signing.loads.
+    """
+
+    @staticmethod
+    def dumps(obj):
+        return pickle.dumps(obj)
+
+    @staticmethod
+    def loads(data):
+        return pickle.loads(data)