lock dub selections to a combination that successfully builds

- vibe.d-rc.3
load disqus over same schema as hosting page

- support for https hosting
remove google ad footer

- see https://github.com/D-Programming-Language/dlang.org/pull/626
Merge pull request #150 from MartinNowak/dplDocs

some dpl-docs fixes (building docs 2.066.1)