Dhalang doesn't work on Windows

[NielsSteensma]

When using Dhalang on Windows the following error would appear originating from the JS scripts:
Unexpected token '\', "\{"webPage"... is not valid JSON

It's related to the fact that in Nodescriptinvoker.create_node_command#26 we call Shellwords.escape; this method is meant for Unix shells.

Action points:

• State in documentation library doesn't work when using a non Unix shell.
• Consider crossplatform shellword escaping ( like in Fastlane )