Correct protocol/action initial values provided to UpdateRule

Currently protocol/action initial values in UpdateRule are incorrectly
formatted: neutron returns lowercase protocol/action strings but
UpdateRule form expects uppercase strings as initial values which
implies to reorder protocol/action choices to select the right initial
values.

This change corrects initial values provided to UpdateRule which allows
to remove the trick in UpdateRule.__init__ and initial protocol/action
values become translatable.

Change-Id: I7145dd591581a7e5e3fb0591518d0e1564f38c10
allow empty device name when launching an instance

From comment 9 on Nova bug 1337821, the device name should be optional
and can cause issues if we force the user to select one and they enter
an incorrect value. We should make the field optional (and make sure
we still create the instance correctly in these cases.)

Change-Id: I7745b67bc52bbfbb98aa223b6e14ae2f96d81339
Closes-Bug: 1339760
display boolean and json parameters in stack launch form

Horizon fails to render boolean and json parameters properly in the
stack launch form, instead of rendering these fields it renders a
duplicate of the previous field.

Change-Id: Idb2fcf4b52578951fb578138a80529eefc140d1a
Closes-Bug: 1360495
Updates to horizon settings.rst

Added documentation for auto_fade_alerts.

Also added to the OpenStack section documentation for:
OPENSTACK_API_VERSIONS,
OPENSTACK_KEYSTONE_MULTIDOMAIN_SUPPORT,
OPENSTACK_KEYSTONE_DEFAULT_DOMAIN,
OPENSTACK_KEYSTONE_BACKEND,
CONSOLE_TYPE,
TROVE_ADD_USER_PERMS,
TROVE_ADD_DATABASE_PERMS.

In the Django section, added ALLOWED_HOSTS
and a note about use of SECRET_KEY.

Closes-Bug: #1221115
Change-Id:  I16596fef2af62b892cef00ab25e2bfe4a80e1c65
Merge "allow empty device name when launching an instance"
Merge "Correct protocol/action initial values provided to UpdateRule"
Merge "display boolean and json parameters in stack launch form"
Merge "Updates to horizon settings.rst"