Add an option to generate site-BDII provider LDIF.

This new option should be used only in the case
that the cloud-info-provider is executed as
one of the providers of a site-BDII (not recommended
in production)
Moved to a function the logic for getting the suffix.
Added test for the new _get_suffix function.
Allow to specify the templates schema.
Removed python-novaclient dependency.
Preparation of release 0.5