requiring v0.4.2 of markdown plugin, and removed marked dep from core, as it didn't seem to be used.

package.json

@@ -32,11 +32,10 @@
     "gm": "1.14.2",
     "gravatar": "1.0.6",
     "less": "~1.6.3",
-    "marked": "0.2.8",
     "mkdirp": "~0.3.5",
     "nconf": "~0.6.7",
     "nodebb-plugin-dbsearch": "0.0.9",
-    "nodebb-plugin-markdown": "~0.4.1",
+    "nodebb-plugin-markdown": "~0.4.2",
     "nodebb-plugin-mentions": "~0.5.0",
     "nodebb-plugin-soundpack-default": "~0.1.1",
     "nodebb-theme-lavender": "~0.0.26",