Add pre compiled binaries for windows, mac and linux

Adds pre compiled binaries for all 3 major platforms using node-pre-gyp. This is the same thing we did and are using in node-serialport and has worked great so far, we also have PR pending that does the same for node-opencv.

@creationix after merging I do need your help to generate the secure keys in travis and app-veyor (since they are repo and account bound respectively). We also need to create a new branch for OSX pre-compiled binaries called osx-binaries, since travis does not support multiple OS builds, so we need a different branch to compile for OSX.

I'm creating a publishing-binaries.md file to describe the process, I'll added a make task to make it easier to generate the binaries with each release.

BTW we at  [The Hybrid Group](https://github.com/hybridgroup) ([hybridgroup.com](http://hybridgroup.com/)) are sponsoring the AS3 buckets, we are also doing it for node-serialport (as mentioned above) and we'll be adding them for node-opencv shortly.

Regards,