Repo: Rename project to nbgather

This package name was available on npmjs and adheres to the `nb`
convention of other notebook plugins, like `nbdiff` and `nbdime`.

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "gather",
+  "name": "nbgather",
   "version": "0.3.0",
   "keywords": [
     "jupyter",

src/main/main.ts

@@ -66,7 +66,7 @@ export class CodeGatheringExtension
     this._documentManager = documentManager;
     this._notebooks = notebooks;
     this._gatherModelRegistry = gatherModelRegistry;
-    settingRegistry.get('gather:plugin', 'rules').then(data => {
+    settingRegistry.get('nbgather:plugin', 'rules').then(data => {
         if (JSONExt.isArray(data.composite)) {
           let dataCompositeObject = data.composite as JSONArray;
           this._sliceConfiguration = dataCompositeObject as SliceConfiguration;

src/util/log.ts

@@ -50,10 +50,10 @@ export function log(eventName: string, data?: any) {
 
   if (_settingRegistry != undefined || _settingRegistry != null) {
     
-    _settingRegistry.get('gather:plugin', 'loggingEnabled').then(loggingEnabled => { 
+    _settingRegistry.get('nbgather:plugin', 'loggingEnabled').then(loggingEnabled => { 
       if ((typeof(loggingEnabled.composite) === 'boolean') && loggingEnabled.composite) {
 
-        _settingRegistry.get('gather:plugin', 'loggingId').then(loggingId => {
+        _settingRegistry.get('nbgather:plugin', 'loggingId').then(loggingId => {
           if (typeof(loggingId.composite) === 'string') {
             postData.loggingId = loggingId.composite as string;