Fix an issue with the cursor sometimes disappearing when a patch was received

Update CodeMirror to the latest version (5.13.2)

www/code/codemirror-5.13.2/package.json

@@ -0,0 +1,28 @@
+{
+    "name": "codemirror",
+    "version":"5.13.2",
+    "main": "lib/codemirror.js",
+    "description": "In-browser code editing made bearable",
+    "license": "MIT",
+    "directories": {"lib": "./lib"},
+    "scripts": {
+      "test": "node ./test/run.js",
+      "lint": "bin/lint"
+    },
+    "devDependencies": {"node-static": "0.6.0",
+                        "phantomjs": "1.9.2-5",
+                        "blint": ">=0.1.1"},
+    "bugs": "http://github.com/codemirror/CodeMirror/issues",
+    "keywords": ["JavaScript", "CodeMirror", "Editor"],
+    "homepage": "http://codemirror.net",
+    "maintainers":[{"name": "Marijn Haverbeke",
+                    "email": "marijnh@gmail.com",
+                    "web": "http://marijnhaverbeke.nl"}],
+    "repository": {"type": "git",
+                   "url": "https://github.com/codemirror/CodeMirror.git"},
+    "jspm": {
+      "directories": {},
+      "dependencies": {},
+      "devDependencies": {}
+    }
+}