Centralize all mutations at the model level

This commit uses a new package that I need to document. It tries to
solve the long-standing debate in the Meteor community about
allow/deny rules versus methods (RPC).

This approach gives us both the centralized security rules of
allow/deny and the white-list of allowed mutations similarly to Meteor
methods. The idea to have static mutation descriptions is also
inspired by Facebook's Relay/GraphQL.

This will allow the development of a REST API using the high-level
methods instead of the MongoDB queries to do the mapping between the
HTTP requests and our collections.

client/components/boards/boardArchive.js

@@ -22,13 +22,9 @@ BlazeComponent.extendComponent({
   events() {
     return [{
       'click .js-restore-board'() {
-        const boardId = this.currentData()._id;
-        Boards.update(boardId, {
-          $set: {
-            archived: false,
-          },
-        });
-        Utils.goBoardId(boardId);
+        const board = this.currentData();
+        board.restore();
+        Utils.goBoardId(board._id);
       },
     }];
   },