Fix display real issue in fuzzy.
* helm.el (helm-fuzzy-matching-default-sort-fn,
helm-fuzzy-matching-default-sort-fn): Do it.

* helm-command.el: Use display prop to add key info.
* helm.el (helm-fuzzy-match-mode): New minor-mode.
* helm-command.el: Use it.
Reenable a function transformer with no sorting for history.
Make a generic function for fuzzy sorting.

* helm.el:
(helm-fuzzy-matching-default-sort-fn-1): New.
(helm-fuzzy-matching-default-sort-fn): Use it using by default display.

* helm-command.el (helm-M-x): Use a specialized sort command based on real.
(helm-M-x-transformer-1): No need to use 'display prop.
Remove global fuzzy mode.

* helm.el (helm-fuzzy-match-mode): It is better to not use a global mode here,
disable it.

* helm-command.el (helm-M-x-fuzzy-match): New user var.
Use defsubst in some places.

* helm.el (helm-score-candidate-for-pattern,
helm--mapconcat-pattern): Do it.