Fixes another off-by-one issue when diffing with caching

Refactored commands and blame annotations

src/commands/toggleCodeLens.ts

@@ -0,0 +1,15 @@
+'use strict'
+import {TextEditor, TextEditorEdit} from 'vscode';
+import {EditorCommand} from './commands';
+import {Commands} from '../constants';
+import GitProvider from '../gitProvider';
+
+export default class ToggleCodeLensCommand extends EditorCommand {
+    constructor(private git: GitProvider) {
+        super(Commands.ToggleCodeLens);
+    }
+
+    execute(editor: TextEditor, edit: TextEditorEdit) {
+        return this.git.toggleCodeLens(editor);
+    }
+}