Added assignment history and unassignment feature (not yet tested).

imports/api/asset-assignment-history.js

@@ -0,0 +1,14 @@
+import {Mongo} from "meteor/mongo";
+
+export const AssetAssignmentHistory = new Mongo.Collection('assetAssignmentHistory');
+
+/*
+Maintains a historical record of asset assignments.
+assetId: The asset's assigned ID (not a MongoID).
+assigneeType: One of 'Student' or 'Staff'.
+assigneeId: The MongoID of the student or staff the asset was assigned to.
+startDate: The date/time of the assignment.
+endDate: The date/time of the unassignment.
+startCondition: TODO
+endCondition: TODO                 
+ */