updated: re-implemented search to check titles, content and replies per search term.
Updated about page links to the relevant about subpages

(cherry picked from commit 645f6f9d8749b3660e170f2a793ffaafb051e7df)
fixed: move to left joins to loosen constraints.
tweaked: improve latest update time for engage post, and don't leak content of new engage posts into next reply.
tweaked: changed icon for accept and unaccept menu entry to be less confusing.
tweak: promote search bar ahead of entering a new response.
updated: only allow OP's of questions to update the status.
tweaked: force new questions into a need answer state.
added: ability to delete engage items.
added: engage guidelines and ensure gravatar gets use the same scheme as the host site.
Merge branch 'master' into content-update

Conflicts:
	upstream/templates/about.html.ep
	upstream/templates/engage.html.ep
added some more fixes that Jim found