[PATCH] A few small additions and corrections to README

Here's a small patch which

 - adds a few archs to the current list of supported platforms.
 - adds a few missing slashes at the end of URLs.
 - adds a few references to additional documentation.
 - adds "make config" to the list of possible configuration targets.
 - makes a few other minor changes.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
[ Ben Nizette <ben.nizette@iinet.net.au> points out AVR32 arch too ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>