Early work on file stuff.

models/file.go

@@ -19,4 +19,17 @@ type File struct {
 // ChangeObject in GQL.
 func (*File) IsChangeObject() {
 	panic("this method is a dummy, and so is its caller")
-}
+}
+
+// A FileFilter is a filter that can be used to filter files.
+type FileFilter struct {
+	Author    *string
+	Public    *bool
+	MimeTypes []string
+}
+
+// A FileUpdate is a set of changes possible to do on file metadata.
+type FileUpdate struct {
+	Public *bool
+	Name   *string
+}