* ivy.el (ivy-read-action): Update prompt for "C-M-a".
* counsel.el (counsel--find-symbol): Use ivy-window.
(counsel--descbinds-cands): New defun.
(counsel-descbinds-history): New defvar.
(counsel-descbinds-action-describe): New defun.
(counsel-descbinds-action-find): New defun.
(counsel-descbinds-action-info): New defun.
(counsel-descbinds): New command. Very similar to `counsel-M-x', except
that only bound commands are displayed.