Does not detect Node.JS on Debian or AWS by default

[benmccann]

We require node to be on the path. See https://github.com/typesafehub/js-engine/blob/master/src/main/scala/com/typesafe/jse/LocalEngine.scala#L69

Apparently Debian calls it nodejs because there's another package named node already. That means we should probably check for nodejs first and prefer it in case the user also has node installed.

I generally don't like installing the version of node that comes with the system package manager and typically prefer nvm

Workaround for these systems: Install nodejs-legacy, which adds symlink /usr/bin/node -> nodejs.