Install Scripts: Add 2 assumed dependencies, Fix EWD.js restart

Python and curl were assumed to be installed by default, add them to the
apt-get install line for bootstrapping the system

EWD.js when restarted can take a few extra seconds to stop. Add a 5
second sleep to ensure the main EWD.js process has stopped.

Change-Id: I0e3e8679d05a40fca64ddc513ca6daa1d8efbb9b