Use VS Color Theme Editor to create theme

[egeerardyn]

We should look into creating this theme using Visual Studio Color Theme Editor instead of the current approach via another website.

The main advantage is that this theme editor is way more complete. In VS2015, by just using the website, my current line is shown in a poor color. With the theme editor, I can get better results.

If we go this route, we might also submit a copy of the theme to https://github.com/PeteW/VisualStudioThemes which bundles some themes.