Update CodeMirror to version 5.49.0 (#8381)

* Update CodeMirror to version 5.49.0

* Update CodeMirror versions in librejs and VERSIONS

public/vendor/plugins/codemirror/addon/lint/yaml-lint.js

@@ -0,0 +1,41 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: https://codemirror.net/LICENSE
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
+})(function(CodeMirror) {
+"use strict";
+
+// Depends on js-yaml.js from https://github.com/nodeca/js-yaml
+
+// declare global: jsyaml
+
+CodeMirror.registerHelper("lint", "yaml", function(text) {
+  var found = [];
+  if (!window.jsyaml) {
+    if (window.console) {
+      window.console.error("Error: window.jsyaml not defined, CodeMirror YAML linting cannot run.");
+    }
+    return found;
+  }
+  try { jsyaml.loadAll(text); }
+  catch(e) {
+      var loc = e.mark,
+          // js-yaml YAMLException doesn't always provide an accurate lineno
+          // e.g., when there are multiple yaml docs
+          // ---
+          // ---
+          // foo:bar
+          from = loc ? CodeMirror.Pos(loc.line, loc.column) : CodeMirror.Pos(0, 0),
+          to = from;
+      found.push({ from: from, to: to, message: e.message });
+  }
+  return found;
+});
+
+});