Glance: Change seed json to use config hierarchy

Change the Glance section of the seed json to use
the new hierarchical Glance param style (glance.api.param/
glance.registry.param).

Change-Id: I28073cef5c9b4cd6087c4f375a2394d612fe8dd7
Enable Galera clustering

The current galera installation does not support clustering. This patch
contains a few fixes and enhancements to allow multiple galera nodes to
join a single cluster.

Change-Id: If71585a4ff7b574d7e83f7dc9cc45239bd36dfc0
Merge "Glance: Change seed json to use config hierarchy"
Merge "Enable Galera clustering"