FreeBSD networking updates

Changes to commands/freebsd/network.py

1. We're missing the restart of freebsd routing service. In addition to restarting /etc/rc.d/netif, we'll also need to restart the routing with: "/etc/rc.d/routing restart". Both netif and routing appear to be necessary for fully restarting the FreeBSD networking stack.

2. subprocess.Popen is clearing out the environment with 'env={}'. Clearing out the environment on freebsd appears to affect the restart of the netif and routing services as freebsd is unable to load the environment and unable to source additional files. With 'env={}' in place, the services did not appear to properly restart.

3. Updating the generation of static_routes in rc.conf file. The format 'static_routes="XXXX,YYYY" is incorrect and the comma ',' needs to be a space ' ', per: http://www.freebsd.org/doc/handbook/network-routing.html

Cheers,
Nick