Move registry to separate file.

django_components/component_registry.py

@@ -0,0 +1,21 @@
+class AlreadyRegistered(Exception):
+    pass
+
+class NotRegistered(Exception):
+    pass
+
+class ComponentRegistry(object):
+    def __init__(self):
+        self._registry = {}  # component name -> component_class mapping
+
+    def register(self, name=None, component=None):
+        if name in self._registry:
+            raise AlreadyRegistered('The component "%s" is already registered' % name)
+
+        self._registry[name] = component
+
+    def unregister(self, name):
+        if name not in self._registry:
+            raise NotRegistered('The component "%s" is not registered' % name)
+
+        del self._registry[name]