Add an update-nth book to std/lists (fixes issue 60).
Document cowles/ and arithmetic/.

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2419 303c5b2c-9740-0410-b014-fd8f9db7be32
Gracefully fail for IE8 and IE9. (fixes issue 130)

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2420 303c5b2c-9740-0410-b014-fd8f9db7be32
Fixing a typo in the :doc topic HIDE

git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2421 303c5b2c-9740-0410-b014-fd8f9db7be32