* ivy.el (ivy-minibuffer-map): Bind "C-c C-a" to `ivy-toggle-ignore'.
(ivy-use-ignore): New defvar.
(ivy-toggle-ignore): New command to toggle ignore
patterns (user-configured filtering). If the ignore patterns are enabled
and there are zero candidates after ignoring, display the ones that
match the current text. This feature currently works for
`ivy-switch-buffer' and `counsel-find-file'.
(ivy--buffer-list): Simplify.
(ivy--switch-buffer-matcher): New defun.
(ivy-switch-buffer): Use `ivy--switch-buffer-matcher'.
* counsel.el (counsel--find-file-matcher): Use `ivy-use-ignore'.