Make sure we can see default network

Source the virsh profile before doing network setup to make sure
the default network is visible to the regular user.  This is
required so the tripleo-incubator scripts will work.
Set --min-tmpfs in images.sh

With less than 4 GB of tmpfs space image builds seem to fail.
Require at least that much tmpfs, otherwise fall back to normal
filesystem tmp space.
Change min-tmpfs to 3

Setting it to 4 would prevent it from using tmpfs even on my 8 GB
VM because the tmpfs size there is set to 3.9 GB (which works fine).
Setting the minimum to 3 will still prevent it from being used on
my 6 GB system because that has a tmpfs size of 2.8 GB (which does
not work).
Merge remote-tracking branch 'origin/master' into slagle/package

Conflicts:
	bin/images.sh
Better logic for deleting old iptables rules when $CONTROL_IP has changed.
Make a new configurable IP for the LEAF for the IP address that should be used
for the br-ctlplane interface where dnsmasq binds to for pxe.