Linux build

Hi Chris,
please see https://github.com/LightTable/LightTable/issues/977 and see my
commit messages for explanation and/or description of what I've done.
Or just simply ask me!

Bost
Not sure I like the script changing branches on me. Since it's only affecting the submodule within deploy it's probably not a big deal though (when developing the plugin I'd have it in my `~/.config/LightTable/plugins` dir).