Update build dependencies and electron setup

[muffinista]

Hi! First off, thanks for this library, I find it very useful in a project I manage.

I wanted to clean up the dependencies for my project a bit, so I've removed the code for doing prebuilds -- if that's important to the project, I'm sure it can be restored. . I also moved electron and a couple assorted of dependencies into their own package.json in the examples folder. Finally, I updated the example code for newer versions of electron, where using remote isn't really an option.