Horizon now has multiple configuration options for the default web URL
(WEBROOT), static file location (STATIC_ROOT) and static file URL
(STATIC_URL) in its settings files.
Themes have moved location from openstack_dashboard/static/themes, to
openstack_dashboard/themes. Paths may need to be updated accordingly.
Furthermore, Horizon is aligning closer with Bootstrap markup, and themes
should be built around this ideology; see the top bar and side navigation for
details.
The deprecated OPENSTACK_QUANTUM_NETWORK configuration option has been
removed. If you still use it, you need to replace it with
OPENSTACK_NEUTRON_NETWORK.
Horizon requires both a volume and volumev2 endpoint for Cinder, even
if only using v2.
Many JavaScript files and most notably the base page template
(horizon/templates/base.html) have moved from the framework portion of
the repo (horizon) to the application side (openstack_dashboard) to
better separate the framework from the application.