Add a binding for skeleten-ecompletion.

To align it with the browse-kill-ring, because when they differ for no
reason, it is very annoying to mistake one with the other.

Signed-off-by: Bao Haojun <baohaojun@gmail.com>
Make case-fold-search more smart.

Signed-off-by: Bao Haojun <baohaojun@gmail.com>
symbol completion should respect mark-active

Signed-off-by: Bao Haojun <baohaojun@gmail.com>