grunt-contrib-jasmine-node doesnt exist anymore and performance isArray

it looks like grunt-contrib-jasmine-node is renamed to grunt-jasmine-node, since it isnt being maintained by the grunt team. npm install will fail because of this.
https://npmjs.org/package/grunt-contrib-jasmine-node
https://npmjs.org/package/grunt-jasmine-node

I have also changed the isArray method by a faster one, see benchmarks at the jsperf site:
http://jsperf.com/array-isarray-vs-angular-isarray/2