why is node_modules checked in?

As far as i can see in the commits in the node_modules dir, there was never an intentional checkin of the node modules. it was most likely an oversight, and lack of a node .gitignore which makes the project unnecessarily heavy to clone :)

this commit adds a standard node gitignore, and removes node_modules

https://github.com/cesine/mobile-chrome-apps/commits/master/node_modules/cordova/package.json