Rework redirections of old content

Add redirect for old locations.

Fix redirects to go to current location.

Use redirectmatch for those guides that are completely reorganized
so that all links will go to the index.html page.

Change-Id: I59c61b77d6f11cc577930e389dfb21fec91644ad
Add havana/index.html file

Prepare for Havana launch and add an index page. It currently links
to trunk for everything, so we need to adjust this when we build
for havana.

Change-Id: I20a04864350811efbb21b11de879737f6725e2af
Merge "Rework redirections of old content"
Merge "Add havana/index.html file"