CA-113319: LicenseManager was showing confusing licensing information.

Signed-off-by: Konstantina Chremmou <konstantina.chremmou@citrix.com>
CA-113431: Display a warning when a pool has a mixture of free hosts with license
expiry dates that are more than 30 days apart (not ideal, but safest solution for
the case of a mixture of free and free but expiring soon hosts.)

Signed-off-by: Konstantina Chremmou <konstantina.chremmou@citrix.com>