Stub additional FloatingIP methods in FlatManager

Fixes bug #989746.

Added some stub methods for floating ip allocation in FlatManager in
order to prevent exceptions from being raised when they are called.

Changed get_floating_ip_by_address() in FlatManager to return a dict
with expected keys for a floating ip, rather than None.

Updated patch from Andrew Laski and added unit tests.

Change-Id: I4ee1f5cf986b6f3411605aae5c1bc4e8cc2377b1
Assign unique names with os-multiple-create.

This patch introduces a new configuration option,
multi_instance_display_name_template, which makes
it so that all instances are given a unique
display_name and hostname when requesting that
multiple instances get created at the same time.

Implements bp multi-boot-instance-naming

DocImpact

Change-Id: Id8e7dac1adadbb101dd1027807867ab13d3b7e80
Merge "Assign unique names with os-multiple-create."
Merge "Stub additional FloatingIP methods in FlatManager"