Passing common parameters to all isolates of one node

[debbabi]

It is needed to have the possibility to passe several parameters to all the isolates of one node.

Whan starting the node, we could set several parameters (using --envs for instance).
These parameters are passed to all the isolates (Python and Java).
We should have an internal service that allows retrieving these parameters.
We could use system environment variables to store these parameters.

[ogattaz]

@see
https://stackoverflow.com/questions/2231227/python-subprocess-popen-with-a-modified-environment

import subprocess, os
my_env = os.environ.copy()
my_env["PATH"] = "/usr/sbin:/sbin:" + my_env["PATH"]
subprocess.Popen(my_command, env=my_env)