Null object exception

Added null check to avoid unhandled exception crashing VS.
Extensions: Rescue from throwing exception.(#863)
JsHint: Config updated based on release notes.
https://github.com/jshint/jshint/releases/tag/2.5.0
Merge pull request #861 from DotNetSparky/master

Null object exception
Merge pull request #865 from am11/extension

Extensions: Rescue from throwing exception.(#863)
Merge pull request #869 from am11/Config

JsHint: Config updated based on release notes
MEF: Treat ContentType Node.js as JavaScript.
Fixes #860.