Use tokens (vs. RegExp) for identifying fenced code blocks (fixes #151, fixes #152, fixes #155).

test/fenced-code-in-list.json

@@ -0,0 +1,6 @@
+{
+  "default": true,
+  "MD013": {
+    "code_blocks": false
+  }
+}

test/fenced-code-in-list.md

@@ -0,0 +1,35 @@
+# Heading
+
+- Item
+
+  ```javascript
+  debugger;
+
+
+  debugger;
+  ```
+
+  text
+
+- Item
+
+  - Subitem
+
+    ```javascript
+    debugger;
+
+
+    debugger;
+    ```
+
+    text
+
+  - Subitem
+
+- Item
+
+  - Subitem
+
+    ```javascript
+    debugger; debugger; debugger; debugger; debugger; debugger; debugger; debugger; debugger; debugger;
+    ```

test/fenced-code-unmatched.md

@@ -0,0 +1,13 @@
+# Heading
+
+Text
+
+```code```
+
+Text
+
+```javascript
+var x = 5;
+```
+
+Text