following customizations for the predefined networks
created on startup (default in parenthesis):
PRIVATE_SUBNET_NAME - Name of the local subnet (private-subnet)
PUBLIC_SUBNET_NAME - Name of the public subnet (public-subnet)
PUBLIC_NETWORK_GATEWAY - IP for the public subnet (172.24.4.225)
Moved NETWORK_GATEWAY into lib/quantum, along with these new
customizations.
bug 1194218
Change-Id: I87ebc22e338df278db7523f11be07de1ca88234b