Sumit with GET method to the iframe for multipart Ajax submit in PhantomJS/NodeJS.

For some reason POST doesn't work (error message: Cannot POST to http://localhost:post/test/js/data/submitNestedForm.xml?...)
Add grunt-cli as dev dependency, so 'npm install' is enough to prepare the test environment
Add 'jshint' to the default tasks.

Fix some JSHint errors
Fix the Grunt task for 'npm test'