Minor adjustments

* Scrolling is now more reliable.

* Improve SIP functionality.

* Adapt some code to 24.3.1, rescan settings.

* Use kbd-style names in `define-keys', now that it doesn't require
  loading more code.

* Improve isearch: make new functionality available (mostly on M-...).

* Improve `eli-next-buffer-acyclic': can choose a window from
  `window-prev-buffers', including windows that are visible in other
  windows as long as they were selected in the current window.  Also use
  it to restore the window-start and position when known.

* Add some new combinations to special-chars, and improve its use in
  case of switching to a different buffer while the input method is
  active.