Initial implementation of Edit mode (#2181)

* Adding edit mode API and buttons

* Select navigated object by default. Enable table configuration in edit mode.

* Fixed issue with Table configuration

* Removed debugging code

* Added basic documentation to Editor API

* use selectable, table is selection[0], inspector cleans up

Update browse to set selection using openmct.selection.selectable
on navation so that selection contexts can be determined correctly.

Update table configuration to reference the first item in selection
instead of the last item in selection when displaying.

Update inspector code to remove display node from document on destroy.

* properly remove capturing handler

* inspector views respond to editing

InspectorViews respond to editing instead of openmct rerendering
the inspector on edit.

src/api/Editor.js

@@ -0,0 +1,83 @@
+
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2018, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+
+import EventEmitter from 'EventEmitter';
+
+export default class Editor extends EventEmitter {
+    constructor(openmct) {
+        super();
+        this.editing = false;
+        this.openmct = openmct;
+    }
+
+    /**
+     * Initiate an editing session. This will start a transaction during
+     * which any persist operations will be deferred until either save()
+     * or finish() are called.
+     */
+    edit() {
+        this.editing = true;
+        this.getTransactionService().startTransaction();
+        this.emit('isEditing', true);
+    }
+
+    /**
+     * @returns true if the application is in edit mode, false otherwise.
+     */
+    isEditing() {
+        return this.editing;
+    }
+
+    /**
+     * Save any unsaved changes from this editing session. This will
+     * end the current transaction.
+     */
+    save() {
+        return this.getTransactionService().commit().then((result)=>{
+            this.editing = false;
+            this.emit('isEditing', false);
+            return result
+        }).catch((error)=>{
+            throw error;
+        });
+    }
+
+    /**
+     * End the currently active transaction and discard unsaved changes.
+     */
+    cancel() {
+        this.getTransactionService().cancel();
+        this.editing = false;
+        this.emit('isEditing', false);
+    }
+
+    /**
+     * @private
+     */
+    getTransactionService() {
+        if (!this.transactionService) {
+            this.transactionService = this.openmct.$injector.get('transactionService');
+        }
+        return this.transactionService;
+    }
+}