Install libffi-dev in the glance element

Installing the glance element standalone requires libffi-dev, users
wouldn't normally hit this in devtest as glance is built with other
elements so its already installed.

Change-Id: Ia96079320c07b87ba1660543a5fd50b3adc14da8
Drop dnsmasq_range from the seeds config.json.

We don't make use of dnsmasq_range anywhere so lets remove it.

Change-Id: Id3e14aee8a9f720a09bc2c8ace99e06c4a2d09a9
Merge "Drop dnsmasq_range from the seeds config.json."
Merge "Install libffi-dev in the glance element"
Adding baremetal guard to RamWeigher

-negative RAM weight should be only for
 undercloud (baremetal)
-this is quick fix, patch that is making it
 configurable via heat is coming

Change-Id: I96bf33eae7fa1e36c788bab957cf88e291f50fa0
Fixes-bug: #1300458
Merge "Adding baremetal guard to RamWeigher"