LIBCLOUD-550_DisplayName

Added support for "displayname" CloudStack deployment parameter and removed automatic setting of "name" parameter.

This will allow for deployment of instances without a hostname, but with a displayname, so that you can have multiple tenants using the same displayname with unique hostnames being generated from the instance UUID.

Closes #289

Signed-off-by: Tomaz Muraus <tomaz@apache.org>