Fixed more versioning issues

Although the nodewebkit npm package tracks the same versions as node-webkit, it can also have patch/build versions which we need to filter out.

Running apps in node-webkit is now working on linux, I need to do more testing with building, but at least now it's downloadng the correct node-webkit version :+1: 

I now understand why this bit of code existed: https://github.com/mllrsohn/node-webkit-builder/blob/2ea258caf6e54a5f0f4ecaf8e21cc73cbc5114de/lib/versions.js#L17