In order to get a proper support for authenticated endpoints, this patch
creates a new definition (tripleo::haproxy::userlist) and exploit it in
the dynamic endpoint (tripleo::haproxy::service_endpoints) as well as
standard tripleo::haproxy::endpoint.
It also detected a small issue with the "underscorization" of the
service name, the missing 'G' flag for regsubst, that preventend all
dashes to be replaced by underscores.
Change-Id: Ie7471155d1ef3f6adc177a468b81ac410bbfb9c0
Closes-Bug: 1736132
9d438cd142