Make help link point to SUSE Cloud guides (bnc#830265)

Based on patch by Nanuk Krinner <nkrinner@suse.de>
(see https://github.com/SUSE-Cloud/horizon/pull/1)

Change-Id: I066c8cac564619047ca15ec07d8c2708c16a5481
Do not require users to be logged in to view the help

Change-Id: I0096a5921f1535bcd190d2d695bcdbfbe42250e2