Changed zipline -> catalyst import paths

* Updated cython build scripts
 * Updated setup.py to to install catalyst package
 * Updated momentum example to use catalyst package
 * catalyst executable now supports loading pipelines from multiple bundles

catalyst/utils/classproperty.py

@@ -0,0 +1,8 @@
+class classproperty(object):
+    """Class property
+    """
+    def __init__(self, fget):
+        self.fget = fget
+
+    def __get__(self, instance, owner):
+        return self.fget(owner)