Fixing undo issue; cleaning up keybindings; removed diplicate focus event

src/app/common/configs/editor.config.ts

@@ -7,7 +7,7 @@ export const EditorSettings: any = {
     CONFIG: {
         behavioursEnabled: true,
         fontSize: "12px",
-        theme: "ace/theme/one_dark",
+        theme: "ace/theme/gruvbox",
         mode: "ace/mode/text",
         printMarginColumn: 80,
         enableBasicAutocompletion: true,

src/app/common/configs/keybindings.config.ts

@@ -8,11 +8,7 @@ export const Keybindings: Array<{}> = [
         bindKey: {win: "F11", mac: "F11"},
         readOnly: false
     }, {
-        name: "showSettingsMenu",
-        bindKey: {win: "ctrl-shift-m", mac: "ctrl-shift-m"},
-        readOnly: false
-    }, {
-        name: "showKeyboardShortcuts",
+        name: "showKeyShortcuts",
         bindKey: {win: "ctrl-shift-k", mac: "command-shift-k"},
         readOnly: false
     }, {

src/app/common/services/editor/files.service.ts

@@ -1,7 +1,7 @@
 import { Injectable, inject } from '@angular/core';
 import { ReplaySubject, Observable } from 'rxjs';
 
-import { EditSession } from 'ace-builds';
+import { EditSession, UndoManager } from 'ace-builds';
 import { getModeForPath } from 'ace-builds/src-noconflict/ext-modelist';
 
 import { TabsService } from './tabs/tabs.service';
@@ -93,7 +93,8 @@ export class FilesService {
             file.session.setMode(
                 getModeForPath( file.path ).mode
             );
-            
+            file.session.setUndoManager( new UndoManager() );
+
             this.files.set(file.path, file);
 	    } catch (error) {
 		    console.log(