Added to system/doc/acl2-doc.lisp for :doc note-6-4:

  There are new analogues of [add-include-book-dir] and
  [delete-include-book-dir]: [add-include-book-dir!] and
  [delete-include-book-dir!], respectively. The new utilities are
  similar to their existing counterparts, except that their effects
  are not [local] to enclosing [books] or [encapsulate] events.
  Thanks to Shilpi Goel for requesting this enhancement.


git-svn-id: http://acl2-books.googlecode.com/svn/trunk@2262 303c5b2c-9740-0410-b014-fd8f9db7be32