Refactor the REST API app

Remove the APIRoot view.

Remove the Endpoint class.

Remove the EndpointSerializer.

Move API documentation generation from the root urls module
to the app's urls module.

Update the app API URL generation to be based on viewsets
instead of an custom api_urls list.

Remove MayanObjectPermissionsFilter and replace it with
MayanViewSetObjectPermissionsFilter which allows mapping
a required permission to a specific viewset action.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/rest_api/generics.py

@@ -0,0 +1,48 @@
+from __future__ import absolute_import, unicode_literals
+
+from rest_framework import generics
+
+from mayan.apps.rest_api.filters import MayanObjectPermissionsFilter
+from mayan.apps.rest_api.permissions import MayanPermission
+
+
+class ListAPIView(generics.ListAPIView):
+    """
+    requires:
+        object_permission = {'GET': ...}
+    """
+    filter_backends = (MayanObjectPermissionsFilter,)
+
+
+class ListCreateAPIView(generics.ListCreateAPIView):
+    """
+    requires:
+        object_permission = {'GET': ...}
+        view_permission = {'POST': ...}
+    """
+    filter_backends = (MayanObjectPermissionsFilter,)
+    permission_classes = (MayanPermission,)
+
+
+class RetrieveDestroyAPIView(generics.RetrieveDestroyAPIView):
+    """
+    requires:
+        object_permission = {
+            'DELETE': ...,
+            'GET': ...,
+        }
+    """
+    filter_backends = (MayanObjectPermissionsFilter,)
+
+
+class RetrieveUpdateDestroyAPIView(generics.RetrieveUpdateDestroyAPIView):
+    """
+    requires:
+        object_permission = {
+            'DELETE': ...,
+            'GET': ...,
+            'PATCH': ...,
+            'PUT': ...
+        }
+    """
+    filter_backends = (MayanObjectPermissionsFilter,)