Adds ability to add project name or id to VM names upon build time

Feature is most useful for flat networks where one may have several
projects/teams in one domain and hostnames are required to be unique
across the network or organisation. This will enable you to add
project_id and project_name to VMs by setting configuration variable
in nova.conf when using multi_instance_display_name_template,
for single instances you'd set single_instance_display_name_template
instead. multi_instance_display_name_template also has been amended
to be able to set project_id and/or project_name.

Added msg level LOG.exception(_LE())
Added and updated unittests

Change-Id: I08799ce330ae2133e666f166cd886d4cb45317d7