underscore: make dep of plugin

Etherpad is deprecating underscore but this plugin uses some pretty extensive features/functionality that are harder to migrate to ES6, so let's just require it for this plugin until ES6 equivalents are well adopted.

commentManager.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const _ = require('ep_etherpad-lite/static/js/underscore');
+const _ = require('underscore');
 const db = require('ep_etherpad-lite/node/db/DB');
 const log4js = require('ep_etherpad-lite/node_modules/log4js');
 const randomString = require('ep_etherpad-lite/static/js/pad_utils').randomString;

index.js

@@ -5,7 +5,7 @@ const settings = require('ep_etherpad-lite/node/utils/Settings');
 const formidable = require('formidable');
 const commentManager = require('./commentManager');
 const apiUtils = require('./apiUtils');
-const _ = require('ep_etherpad-lite/static/js/underscore');
+const _ = require('underscore');
 const readOnlyManager = require('ep_etherpad-lite/node/db/ReadOnlyManager.js');
 
 let io;

package.json

@@ -23,7 +23,8 @@
   ],
   "dependencies": {
     "cheerio": "^0.22.0",
-    "formidable": "^1.2.2"
+    "formidable": "^1.2.2",
+    "underscore": "*"
   },
   "devDependencies": {
     "eslint": "^7.18.0",

static/js/copyPasteEvents.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const _ = require('ep_etherpad-lite/static/js/underscore');
+const _ = require('underscore');
 const randomString = require('ep_etherpad-lite/static/js/pad_utils').randomString;
 const shared = require('./shared');
 

static/js/index.js

@@ -6,7 +6,7 @@
 */
 
 
-const _ = require('ep_etherpad-lite/static/js/underscore');
+const _ = require('underscore');
 const browser = require('ep_etherpad-lite/static/js/browser');
 const commentBoxes = require('ep_comments_page/static/js/commentBoxes');
 const commentIcons = require('ep_comments_page/static/js/commentIcons');