Add Debug Logging Support

Previsouly the openstack::glance class would use the
verbose parameter for debug logging.

This change adds the debug parameter that allows users to
seperate debug and verbose logging levels.

Defauls to 'False' for backwards compatibility and to disable
debug logging.

Change-Id: I55853056e317828faec035cff4b33169b8ee0cfd
Merge "Add Debug Logging Support"