Added a couple of customizations to ido-mode:

* added two keybindings to navigate the work directories in vertical
  mode

* enable ide everywhere

* Inhibit switching to other directory when no matches are found in
  the current directory.

* reduce the max size of work directory list. I expect that this way
  work directory navigation will be more usable.


git-svn-id: svn://localhost/emacslib/emacslib/trunk@453 a9598837-e506-0410-a967-fbf0066ee963