Updated docs/emacs

  * emacs.org: added configuration for Bookmark+ and Dired+, switched to
    use ibuffer (experimental), changed accordingly keybinds;
  * updated (tangled) following TOP/emacs.d files:
    - auctex-us.el;
    - emacs;
    - keybinds-us.el;
    - org-us.el;
    new files:
    - bookmark+-us.el;
    - dired+-us.el;
    - ibuffer-us.el.

Signed-off-by: Vladimir Lomov <lomov.vl@gmail.com>