JBIDE-17039 - "autolink" blog authors to their community.jboss.org page
JBIDE-18417 - Add RSS link in HTML head
JBIDE-18028 - IMPORTANT/URGENT etc. from asciidoc gets no styling

Adding Asciidoctor styles for admonitions.
JBIDE-18399 - JBT website "What's new" page missing Alpha-Beta3 new features

Unset the 'archived: true' attribute for all alpha + beta versions of JBT 4.2.0
Also fixed broken tabs on download pages (active tab was not selected and tab
selection would not trigger a change in the browser location).