[PATCH] Docs update: typos, corrections and additions to applying-patches.txt

Typos/corrections.

A few extra additions on top of Randy's fixes.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>