Add toJSON methods (#1859)

* tojson things

* fix client

* ignore private properties

* remove extra property descriptors

* handle primitive flattening

* remove unused import

* add toJSON to collections

* reduce stateful props

* state

* allow custom prop names when flattening

* fix client

* fix build

* fix flatten docs

* remove guild.available, cleanup permissions, remove arbitrary id reduction

* fix util import

* add valueOf as needed, update member props

* fix incorrect merge

* update permissionoverwrites and permissions

remove serialization of permissions in PermissionOverwrites#toJSON.
change Permissions#toJSON to serialize permissions, by default excluding
admin checks.

* change Permissions#toJSON to return the primitive

* Permissions#toJSON explicitly return bitfield

src/structures/User.js

@@ -258,6 +258,19 @@ class User extends Base {
     return `<@${this.id}>`;
   }
 
+  toJSON(...props) {
+    const json = super.toJSON({
+      createdTimestamp: true,
+      defaultAvatarURL: true,
+      tag: true,
+      lastMessage: false,
+      lastMessageID: false,
+    }, ...props);
+    json.avatarURL = this.avatarURL();
+    json.displayAvatarURL = this.displayAvatarURL();
+    return json;
+  }
+
   // These are here only for documentation purposes - they are implemented by TextBasedChannel
   /* eslint-disable no-empty-function */
   send() {}