Add 4.7R release docs and activate them:

1.52 -> 1.53 includes.sgml
1.78 -> 1.80 releases/index.sgml
(new) releases/4.7R/docbook.css
(new) releases/4.7R/errata.html
(new) -> 1.1 releases/4.7R/hardware.sgml
(new) releases/4.7R/relnotes-alpha.html
(new) releases/4.7R/relnotes-i386.html
(new) -> 1.1 releases/4.7R/relnotes.sgml