Add source download page

Conflicts:
	content/tutorial.html
	layouts/default.html
Add some extra info on source install
Identify correct submenu for source install
Cross-ref source install and repository build FAQ
Use IPv6 manual for examples

Expect website to be using that version by default
Add upgrade page
Merge branch 'master' into test

Conflicts:
	Makefile
	content/index.html
	layouts/default.html