Update dstore/Cache::put (SitePen#154)

Previous behaviour was to remove the item while waiting for return
from the master store.  Now Cache will presume the update will
complete and only remove the item if the master store rejects the
`put`.

Fixes SitePen#117

Cache.js

@@ -141,16 +141,20 @@ define([
 			});
 		},
 		put: function (object, directives) {
-			// first remove from the cache, so it is empty until we get a response from the master store
+			// first update the cache, we are going to assume the update is valid while we wait to
+			// hear from the master store
 			var cachingStore = this.cachingStore;
-			cachingStore.remove((directives && directives.id) || this.getIdentity(object));
-			return when(this.inherited(arguments), function (result) {
+			cachingStore.put(object, directives);
+			return when(this.inherited(arguments)).then(function (result) {
 				// now put result in cache
 				var cachedPutResult =
 					cachingStore.put(object && typeof result === 'object' ? result : object, directives);
 				// the result from the put should be dictated by the master store and be unaffected by the cachingStore,
 				// unless the master store doesn't implement put
 				return result || cachedPutResult;
+			}, function () {
+				// Assuming a rejection of a promise invalidates the local cache
+				cachingStore.remove((directives && directives.id) || this.getIdentity(object));
 			});
 		},
 		remove: function (id, directives) {